Industrial processing of condiments and seasonings and its implications for micronutrient fortification

Transcription

1 Ann. N.Y. Acad. Sci. ISSN ANNALS OF THE NEW YORK ACADEMY OF SCIENCES Issue: Fortification of Condiments and Seasonings with Vitamins and Minerals in Public Health I Industrial processing of condiments and seasonings and its implications for micronutrient fortification Elvira González de Mejia, 1 Yolanda Aguilera-Gutiérrez, 2 Maria Angeles Martin-Cabrejas, 2 and Luis A. Mejia 1 1 Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, Illinois. 2 Instituto de Investigación de Ciencias de la Alimentación (CIAL), Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid, Spain Address for correspondence: Elvira González de Mejia, 228 ERML, MC-051, 1201 West Gregory Drive, Urbana, IL edemejia@illinois.edu Opportunities exist for micronutrient fortification of condiments and seasonings to combat vitamin or mineral deficiencies. This paper reviews the available technologies for industrial processing of condiments and seasonings and their fortification with micronutrients. The industrial processes to manufacture commonly consumed condiments and seasonings, such as soy sauce, bouillon cubes, fish sauce, spices, and other relevant products, are described. The impact of processing on fortification is evaluated, considering both the type of vehicle and the fortificant used. The analyzed technologies represent effective strategies for mineral fortification, particularly with iodine and iron. However, fortification with vitamins has been more challenging, owing to sensory changes of the finished product and a poor stability of the fortificant when using certain vehicles. Therefore, more studies are needed in this area in collaboration with governments, the food industry, and vitamin suppliers. Despite the technical difficulties encountered, the current processing technologies for the production of condiments and seasonings can be adapted and refined to allow their successful fortification with micronutrients. Keywords: fortification; micronutrients; condiments; seasonings; food processing Introduction For many years, traditional vehicles used globally for food fortification have been staple foods, such as flours, salt, and sugar. More recently, China and some countries in Southeast Asia and Central and Western Africa have started to use condiments and seasonings as vehicles for micronutrient fortification to address key dietary insufficiencies, particularly of iodine, iron, and vitamin A. This newer fortification approach has included the use of soy sauce, fish sauce, curry, bouillon cubes, flavored salts, spices, and other flavoring agents such as monosodium glutamate (MSG). This strategy has the advantage that consumption of condiments and seasonings is a culturally well-accepted, frequent, and consistent activity, which uses already-existing delivery channels. 1,2 In order to assess the effectiveness and industrial feasibility of using condiments and seasonings as fortification vehicles, it becomes important to understand the respective technological processes involved in the production and fortification of these products and how these processes affect the overall quality of the finished product, including sensory characteristics, nutrient losses, shelf life, particle size, micronutrient interactions, and food matrix interactions with the fortificants. (It should be noted that the impact of processing on bioavailability, stability of the fortificant, organoleptic properties of the fortified product, cost implications, and effectiveness of clinical studies or national fortification programs are discussed in greater detail elsewhere.) The objective of this publication is to review the current technologies for industrial processing of condiments and seasonings fortified with micronutrients, globally. Specific examples of relevant fortification programs will be provided. On the basis of the interpretation of the available information, recommendations will be given for industrial production of safe and effective fortified products. doi: /nyas Ann. N.Y. Acad. Sci (2015) 8 28 C 2015 New York Academy of Sciences.

2 de Mejia et al. Processing of fortified condiments and seasonings Technologies for industrial production of condiments and seasonings Plants are often used as raw materials to produce condiments or seasonings. Conventional production of plant-based condiments and seasonings implicate losses of volatile compounds as well as hygienic and quality problems, which may bring relevant safety risks for the population. 3,4 In the case of spices, several factors influence their shelf life, including bacterial contamination and changes in metabolic activity, especially enzyme activation Grinding, for example, may cause discoloration and losses of essential oils due to evaporation and oxidative reactions. 11,12 Plant-based condiments are produced from a variety of plant components like leaves, seeds, or barks, and are used either in fresh or dried forms. The different processing steps used in the processing of condiments from plant sources, including inconveniences that may be encountered at each step and their potential solutions, are presented in Figure 1. Plant harvest and postharvest treatments Harvest is manually or mechanically performed and conducted when levels of active components are highest At this stage, fumigation with ethylene oxide and other chemical treatments are often used. 17 Drying Drying is a key processing step for maintaining the shelf life of the finished product by slowing microbial growth and preventing biochemical reactions that may alter sensory characteristics. Unfortunately, drying may also lead to undesirable changes in fragrance and appearance. 18 The process starts by drying the plant raw material using various methods, such as sun drying or drying using stoves, open fires, or heated iron pipes, until reaching a hygienically safe moisture level of about 10% In industrialized countries, drying using mechanical equipment allows for control of drying temperatures (45 60 C), minimizing the loss of volatile oils and discoloration of the plant material and, additionally, achieving better hygienic conditions. 18,20 Another drying method is freeze-drying, which preserves the integrity of heat-sensitive compounds and an appearance characteristic of raw materials, 21 although alterations on the levels of certain volatile compounds may still occur. In practice, the release or retention of volatile compounds from plant materials such as spices due to drying is not predictable and will depend on the compound and the kind of plant material. 22 Cleaning Cleaning is an important step in the production of plant-based condiments and seasonings because this is the part of the process that will assure that the product is not contaminated with foreign materials from a potentially wide variety of sources. At the industrial production level, this step requires expensive specialized equipment, such as magnets, sifters, and various types of mechanical separators, which function by separating the foreign components from the plant material based on their shape or density. As a consequence, significant losses of the real product may occur during the cleaning, something not desirable for the producer. Under rudimentary conditions of small businesses, the cleaning process may be conducted in the open air and even require handpicked separation of foreign material, making the process labor intensive and somewhat inefficient. Owing to the above considerations, proper cleaning is an expensive step in the process. Grinding Grinding is the reduction of particle size of the clean plant material. This is a critical step, because grinding of the material may cause volatility issues and loss of aroma due to the loss of essential oils, major ingredients of spices. 23,24 This is commercially important because the value of most spices is based on a characteristic aroma generated by the content of volatile oils. This phenomenon occurs because grinding ruptures the glands in spices that contain essential oils, which then become free for evaporation or reaction with other substances. To mitigate this volatility problem, grinding temperature must be maintained as low as possible, usually below 90 C, particularly for heat-sensitive materials. Another nontraditional option to minimize the volatility of aromatic essential oils is the use of very low temperatures with liquid nitrogen during the grinding step, a process known as cryogenic grinding. Cryogenic grinding can retain more volatile components, including the lower molecular weight volatile substances, resulting in a wider variety of flavors. Although not widespread, Ann. N.Y. Acad. Sci (2015) 8 28 C 2015 New York Academy of Sciences. 9

3 Processing of fortified condiments and seasonings de Mejia et al. Figure 1. Conventional process for the production of plant-based condiments and seasonings. 10 Ann. N.Y. Acad. Sci (2015) 8 28 C 2015 New York Academy of Sciences.

4 de Mejia et al. Processing of fortified condiments and seasonings cryogenic grinding benefits the industrial processes because there is no heat involved to evaporate some of the moisture, and it also minimizes oxidative deterioration. Ground cinnamon is one example of a finely ground product where cryogenic grinding prevents excessive oil loss. 25 Particle size The particle size for each spice depends on the required utilization. Conventional grinding methods include the use of hammer mills (coarse grinding), plate mills (domestic use), or pin mills (fine grinding). In most cases, spice particles should be small enough that they are not visually obvious or felt by the mouth of the consumer. When the particles can be seen, they need to be subjected to strict granulation specifications. 26 Packaging and storage of the end product Spices should be packed and stored in appropriate packaging materials to maintain stability and prevent contamination. They should be stored at moderately low temperatures, ideally not exceeding 22 C. A relative humidity of below 60% is also essential to prevent microbial growth, oxidation, and enzyme changes and to maintain the stability of the product. Postharvest microbial decontamination The postprocessing treatments are those used to control or reduce microbiological or insect populations found in spices after harvest or during storage. Treatment methods include (1) fumigation with ethylene oxide, a carcinogen, restricted and even prohibited in some countries; (2) irradiation, a legally accepted disinfestation procedure that unfortunately has not found acceptance by consumers (irradiation at high doses could cause oxidation and degradation of aromatic components, which may lead to reductions in volatile compounds during storage; 27 however, properly applied, irradiation can effectively treat insect infestation of grains and bacterial growth 3,28 30 ); (3) steam treatment, which consists of application of high-temperature steam to the whole plant material before grinding; 3,31 (4) microwave, an effective method owing to the high penetration power of radiations in spice products (microwaving of white and black pepper seems to be a sanitization method that guarantees the preservation of main aromatic compounds 32 ); (5) exposure of the spice material to a high temperature for a short duration (unfortunately, this method has not been found to provide protection against microbial growth during storage 33 ); (6) vacuum steam vacuum procedures, after a short steam treatment of the product, consisting of an abrupt evacuation of the treatment chamber, which leads to an intensive reevaporation of the superficial condensate layer with removal of microorganisms from the material; 34 (7) ultraviolet and far infrared treatments (the low penetration power of these treatments might be preferable for surface decontamination of spices without excessive quality damages 31 ); and (8) extrusion technology. This commonly used process in the food industry improves the safety and quality of food ingredients and finished food products in general However, to our knowledge, the use of this potential decontamination procedure is not common. Production of soy sauce, fish sauce, bouillon cubes, monosodium glutamate, and curry Soy sauce. The industrial production process of soy sauce, the most commonly consumed East Asian fermented product, has been fully described by Luh. 39 Manufacturing of this product consists of a two-step fermentation process of soybeans and wheat flour by a mixture of molds, yeast, and bacteria. The manufacturing flow diagram, including critical control points, is presented in Figure 2. The first step involves the production of the culture starter known as koji by fermenting the soybeans and wheat flour with mold to produce proteolytic and amylolytic enzymes that give the characteristic aroma and flavor to the sauce. This is followed by a second fermentation step with yeast and bacteria in the presence of 18 20% salt. The final process is refining, which includes filtering and pasteurizing, and the addition of sodium benzoate as a preservative to the resultant filtered soy sauce solution, which is then bottled. The micronutrients used for the fortification of soy sauce are added at this final refining step. The traditional koji manufacturing process is a manual process, but it can be automated by using modern production lines equipped with continuous cookers, continuous wheat roasters, mechanical mixers, coolers, automatic inoculators, temperature controllers, conveyors, and/or mechanical devices for turning the substrates during fermentation. Ann. N.Y. Acad. Sci (2015) 8 28 C 2015 New York Academy of Sciences. 11

5 Processing of fortified condiments and seasonings de Mejia et al. Figure 2. Generic soy sauce processing diagram. Proposed point of micronutrient addition is designated by dashed arrow. Fish sauce. Fish is a major source of animal protein in several countries in Southeast Asia, and fish fermentation is a low-cost preservation method. The term fish sauce, according to Amano, 40 who has described the manufacturing process, refers to clear, brown liquid hydrolysate from salted fish. According to this author, the manufacturing process for fish sauce may vary in each Asian country, but 12 Ann. N.Y. Acad. Sci (2015) 8 28 C 2015 New York Academy of Sciences.

6 de Mejia et al. Processing of fortified condiments and seasonings Figure 3. Generic fish sauce processing diagram. Proposed point of micronutrient addition is designated by dashed arrow. Optional heating is also shown at two steps with dashed arrows. the basic principle is the same; fish and salt being the main ingredients. The manufacturing process of fish sauce, including the critical control points in the process, is presented in Figure 3. The fish is washed and mixed with salt in 1:1 to 1:5 ratios. The resulting blend is left to ferment at 37 Cforaperiod varying from 6 to 18 months, during which the fish undergoes microbial and enzymatic hydrolysis. Ann. N.Y. Acad. Sci (2015) 8 28 C 2015 New York Academy of Sciences. 13

7 Processing of fortified condiments and seasonings de Mejia et al. The liquid is then skimmed off the top or drained from the bottom of the container. This final step includes separation from fish residues, resulting in a translucent brown liquid known, after filtration, as fish sauce. Fortification with iron and/or iodine takes place at the final steps of the process. Since the traditional manufacturing process of fish sauce may take up to 2 years, soy sauce koji (culture starter) and commercial protease enzymes have been used to accelerate fermentation in the processing of fish sauce from pelagic fish species without affecting the flavor and nutritional quality of the sauce. 41 Bouillon cubes. Consumption of micronutrientfortified bouillon cubes has become popular in countries in Central and Western Africa, Asia, and, more recently, in the Caribbean and Latin America. They are commercialized in different flavors such as vegetables, herbs, onion, garlic, chicken, and beef. The industrial design of the bouillon cube manufacturing process has been discussed by Gupta and Bongers. 42 A simplified process-flow diagram, including critical control points, is shown in Figure 4. All crystalline ingredients (e.g., iodized salt, MSG, sugar) are added into a blender and mixed at low speed for 60 seconds. A third of the water is added and mixed at low speed for another 60 s. All fine powders (e.g., colorants and flavorings, but not starch) and micronutrients, like iron or zinc, are added at this point and mixed for an additional 60 s at low speed. The fat and emulsifier are combined and heated to C, added into the mixer, and mixed at high speed for 30 seconds. The remaining two-thirds of the water is added into the mixer and mixed for other 30 s at high speed. The starch is then added and mixed for 60 s at low speed. The molten fat is solidified during a cooling step known as maturation. 42 The solid mixture is then ground and packed as powder into polyethylene bags or shaped into cubes by a conventional tableting device. Salt. Salt is a commonly used ingredient in the food industry and an essential condiment of all household food preparations. Furthermore, salt has been, for many years, an important vehicle for iodine fortification. In some parts of the world, salt is still manufactured using ancient methods such as evaporation of sea water, but new, more efficient methods have been developed using salt mining from the earth and inclusion of multiple micronutrient fortificants Both the method used and the source of the salt will influence its flavor and texture. For example, sea salt produced by sea water evaporation is preferred for gourmet and home cooking owing to its better flavor given by the presence of impurities, mainly other minerals. On the other hand, table salt and salt used for industrial purposes, which requires a very clean, high-quality and fine-texture product, is mostly produced by salt mining. A manufacturing flow diagram for both sea salt and salt from earth mining is presented in Figure S1. Iodine and other potential micronutrients are usually added to salt after the salt has been refined and dried, by one of two main techniques. The wet method is particularly cost effective; a solution of potassium iodate (KIO 3 ) is either dripped or sprayed at a uniform rate onto salt passing by on a conveyor belt. The alternative method involves sprinkling potassium iodide powder (KI) or KIO 3 over the dry salt (dry method), which requires small homogenous crystals of salt to ensure an even distribution of iodine. Monosodium glutamate. Despite negative consumer perceptions about the safety of MSG, it is a condiment commonly used throughout Asia and as part of East Asian cooking around the world. According to the Codex Alimentarius, MSG is considered safe for human consumption as a flavor enhancer. The industrial production of MSG has been described by Ault. 46 A simplified MSG production diagram is presented in Figure S2. All manufacturing methods of MSG first produce either (S)-glutamic acid hydrochloride or (S)-glutamic acid, which represents the starting point. The glutamic acid is dissolved in water, neutralized by adding sodium hydroxide, and converted to an MSG solution, which is then decolorized by activated carbon and concentrated under vacuum at 60 C before cooling for crystallization, centrifugation, and drying. 46 Curry. Curry is a plant-based condiment consisting of a mixture of more than 30 different spices from around the world. Spices are first flame roasted at about 100 C to remove moisture and to release their aromas. They are then ground as individual powders, measured, and mixed together to become, after aging in a tank for a few days, what we know as curry powder, with its characteristic flavor and aroma (Fig. 5). 14 Ann. N.Y. Acad. Sci (2015) 8 28 C 2015 New York Academy of Sciences.

8 de Mejia et al. Processing of fortified condiments and seasonings Figure 4. Generic bouillon cubes processing diagram. Proposed point of micronutrient addition is designated by dashed arrow. Micronutrients commonly used to fortify condiments and seasonings The micronutrients most frequently added to condiments and seasonings are vitamin A, iron, zinc, and iodine, either singly or in multiple forms depending on the demonstrated micronutrient deficiency in the target population. 47,48 Selection of the proper chemical form of the fortificant will depend on a balance of several factors, such as cost, bioavailability, consumer acceptance, and stability. The cost of the fortificant will influence the cost of the finished fortified product and, if significantly higher than the unfortified product, it may not be afforded or accepted by consumers. Bioavailability of the micronutrient is of foremost importance since it should be absorbed by the body in sufficient amount to effectively contribute to improving the micronutrient deficiencies of the target population. Some fortificants, when added to certain food vehicles, may also cause organoleptic changes in flavor, color, or general appearance of the fortified product Ann. N.Y. Acad. Sci (2015) 8 28 C 2015 New York Academy of Sciences. 15

9 Processing of fortified condiments and seasonings de Mejia et al. Figure 5. Generic curry processing diagram. Proposed point of micronutrient addition is designated by dashed arrow. that make it unacceptable by the consumer. The shelf life of the fortified product is also critical, because if sensory changes as described above appear, the product may not be accepted by consumers and will need to be discarded after a short time in the market. Poor stability is generally caused by oxidation; the presence of reducing agents, acids, or alkalis; heat, high humidity, or interaction of the fortificant with food matrix components. Discussion of individual characteristics of micronutrients commonly used in fortification of condiments or seasonings follows. Vitamin A Fortification with vitamin A, if the vitamin is not properly protected from the factors indicated above, is challenging, because of its poor stability and the generation of organoleptic changes in the finished fortified product. To cope with these issues, commercial vitamin A preparations have been designed that could be added to foods during or after cooking, or even immediately before consumption, with the objective of not altering the flavor or color of the food. 49 Unfortunately, different studies conducted to assess the effects of vitamin A fortification of MSG in Indonesia, 50,51 of salt seasoning powders in China, and of instant noodles in Thailand 56 have shown that sensory changes of the fortified foodshavebeenacommonissue. 57 The chemical structure of vitamin A, containing several double bonds, it is not very stable during processing, storage, and after cooking, and it is also sensitive to light and oxygen. 58 In addition, such stability is adversely affected when it is added to foods containing more than 7 8% moisture. Heating of 16 Ann. N.Y. Acad. Sci (2015) 8 28 C 2015 New York Academy of Sciences.

10 de Mejia et al. Processing of fortified condiments and seasonings Table 1. Tolerable upper intake level (UL) of micronutrient intakes, their cost, and factors that limit the added amount Tolerable upper Factors limiting the intake levels (ULs) Cost of addition of fortificants Children fortificant Shelf Nutrient (<13 years) Pregnant (US $/ kg) Sensorial life Interactions References Vitamin A ( g) X XX X 50, 51, 60, 61, 77, 109, 133 Vitamin A (SD-250) Vitamin A palmitate Iron (mg) XXX X XX 47, 64, 65, 70, 72, 73, 80, 81, 84, 89 91, 115, 149, 150 NaFeEDTA Ferrous bisglycinate Ferrous fumarate 5.12 FeSO 4, dried 2.35 FeSO 4, encapsulated Electrolytic iron 5.76 Iodine ( g) X X X , 113 Zinc (mg) XX X X 61, 92, 94, 151 Note: X, minor constraint; XX, moderate constraint; XXX, major constraint vegetable oils during repeated frying or deep frying is also known to significantly degrade vitamin A. In the presence of oxygen and light, there can be extensive losses of vitamin A activity through oxidation, which can be accelerated by the presence of trace metals. The addition of antioxidants such as tocopherols may somewhat alleviate the stability issues, but will make the finished fortified product somewhat more costly. As shown in Table 1, factors that limit the addition of vitamin A to foods include organoleptic issues, poor stability affecting the shelf life of the fortified product, and interactions between vitamin A and the food matrix. Different vitamin A preparations, mostly acetate or palmitate, are commercially available in a wide range of forms adapted for use in different food vehicles under various conditions. 59 Mixing with dry products requires dry forms of vitamin A with the appropriate size and density. 60,61 Being a lipid substance, vitamin A is not soluble in water, making it difficult to add to beverages or highly hygroscopic products such as salt. Therefore, water-dispersible or encapsulated forms of vitamin A in a more hydrophilic coat (gum acacia and gelatin) have been developed and are now commercially available to achieve a more water-dispersible product and protection against humidity. However, evaluation of this tactic has resulted in limited success. 62 In addition, the use of encapsulation technologies is more expensive and increases the cost of vitamin A fortification. Iron A lack of iron is one of the most widely prevalent nutritional deficiencies around the world, primarily affecting children and women of reproductive age. Therefore, iron fortification is an important tool to combat such deficiency. One critical and important issue with iron fortification is its bioavailability, which depends on the type of compound used and the intrinsic iron-absorption inhibitors in the diet of the target population. Several iron compounds are currently used as food fortificants, and their level of bioavailability is related to their solubility in water and dilute acid. 63 In general, higher solubility of the fortificant means better bioavailability of the micronutrient. In addition, the greater the presence of dietary inhibitors, like phytates and phosphates, the less the bioavailability of the fortificant. In order to deal with low bioavailability due to iron inhibitors, protected iron forms, such as microencapsulated iron, have been widely used by the food industry. 62 Another more recent option has been the use of chelated iron compounds: owing Ann. N.Y. Acad. Sci (2015) 8 28 C 2015 New York Academy of Sciences. 17

11 Processing of fortified condiments and seasonings de Mejia et al. to their chemical structure, their iron component of the molecule is not susceptible to iron inhibitors in the diet. Thewater-solubleironcompoundferricsodium ethylenediaminetetraacetic acid (NaFeEDTA) is one of these compounds, having one of the highest relative iron bioavailabilities. 64,65 For this reason, NaFeEDTA has been selected as the preferred iron compound to fortify soy and fish sauces for programs in several Asian countries, aimed at reducing the prevalence of anemia in women, 66,67 adolescents, 68 and infants 6 8 months of age. 69 One downside is that the cost of NaFeEDTA as a fortificant may contribute to as much as 8% of the product price, thus risking the sustainability of the programs in developing countries. 70 As indicated in Table 1, the most bioavailable iron compounds, like NaFeEDTA and ferrous bisglycinate, are also the most expensive. For this reason, the water-soluble and less-expensive ferrous sulfate is frequently used in iron fortification of soy and fish sauces. 71,72 Ferrous sulfate is also used to fortify curry powders. 73 However, because the addition of ferrous sulfate to foods produces peptide precipitation during storage, NaFeEDTA is generally added to increase the iron dose to desired fortification levels. 69 Two of the issues when using ferrous sulfate as a fortificant are the poor stability of the fortified product and organoleptic changes due to oxidation. As indicated in Table 1, this affects its addition to foods, generating undesirable sensory characteristics and negative interactions with matrix components. However, ferrous sulfate, stabilized with citric acid, has been successfully used to fortify fish sauce, and may offer a less-expensive alternative to NaFeEDTA. 70 Another soluble iron compound is ferrous bisglycinate, an iron amino acid chelate in which the iron, as in the case of NaFeEDTA, is protected from the action of absorption inhibitors. 74 Ferrous fumarate, a poorly water-soluble substance, has also been a commonly used iron compound to fortify fish sauce, soy sauce, or curry powder. 73,75 78 Using this compound may reduce fortification cost four- to fivefold without altering iron bioavailability. 70 On the other hand, water-insoluble iron compounds, such as ferric phosphate, ferric orthophosphate, and ferric pyrophosphate, have lower iron bioavailability but are significantly cheaper than the soluble compounds and have fewer negative effects on product stability and the organoleptic characteristics of the fortified foods. 79 Therefore, the use of these fortificants is generally considered by the food industry as the best possible solution, even in settings where the diet of the target population is high in iron-absorption inhibitors Iron compounds can also be encapsulated with hydrogenated vegetable oils, but mono- and diglycerides, maltodextrins, and ethyl cellulose have been used as well. A micronized form of ferric pyrophosphate has been developed for use as a food fortificant. 85,86 These alternative iron compounds are available in either liquid or dried forms; however, small submicron particle sizes cannot be achieved by physical grinding, only by a chemical process. 85,87 In the case of fortification of condiments or seasonings, the main disadvantage of the iron-encapsulation option is an increase in the price of the fortified product by as much as 30%. The selection of the iron fortificant also depends on the characteristics of the food vehicle. 88 The color of the iron compound is often a critical factor when fortifying lightly colored foods. In this case, the use of more soluble iron compounds (e.g., iron sulfate) may lead to development of off-colors and off-flavors owing to chemical interactions of the fortificant with other components of the food material. 89,90 Some of these undesirable interactions with the food matrix can be prevented by coating the fortificant with hydrogenated oils or ethyl cellulose. 91 Zinc Several zinc compounds, of diverse solubility and taste, can be used for zinc fortification of foods. This includes oxide, sulfate, chloride, gluconate, and stearate chemical forms. 92 Zinc acetate could be also used as food fortificant, but at present is mainly utilized as a dietary supplement. Zinc oxide is the preferred form because it is the cheapest of the zinc fortificants; although it is poorly water soluble, its bioavailability has been found to be similar to that of zinc sulfate. Currently, zinc fortification of condiments or seasonings has not been attempted, except for the multimicronutrient fortification of seasoning powders. 93,94 Recent studies have shown that zinc fortification of flavoring powders can improve the nutritional status of children and women. 95 Iodine Iodate and iodide are the two chemical forms of iodine compounds (as potassium, calcium, or 18 Ann. N.Y. Acad. Sci (2015) 8 28 C 2015 New York Academy of Sciences.

12 de Mejia et al. Processing of fortified condiments and seasonings sodium salts) suitable for iodine fortification of foods. 96,97 Historically, salt has been the most ancient food vehicle for iodine fortification, using either potassium iodide or potassium iodate. 98,99 The use of each of these compounds has its advantages and disadvantages; iodates are less water soluble and more resistant to oxidation and evaporation and therefore more stable under adverse climatic conditions such as in the tropics. For historical reasons, countries in Europe and North America still use potassium iodide for salt iodization, while most countries with tropical climates use potassium iodate Nutritional deficiencies of more than one micronutrient often coexist in the same target population. Therefore, a new approach has been multiple fortification of the same vehicle. For example, iodine fortification of salt can be performed as a single addition of the iodine fortificant; 100,103 combined with other micronutrients like iron, a process known as double fortification; 85,86, or as triple fortification when, in addition to iodine, iron and vitamin A are added. 106,108,109 Double fortification of fish sauce with iodine and iron has been found to be suitable, beneficial, and cost effective. 105 Based on the well-known health benefits of salt iodization, the WHO recommends and supports the universal iodization of all salt for human or animal consumption and for industrial use. 110 Iodide compounds are cheaper, more soluble, and have higher iodine content than iodates. 112 However, iodates are more stable under conditions of high moisture, high room temperature, sunlight, aeration, and the presence of impurities. The iodides are more easily degraded in the presence of impurities, whereas the iodates remain stable in salts of lower quality. On the other hand, the iodides may be oxidized to molecular iodine and become lost through evaporation. Available technologies for micronutrient fortification of condiments and seasonings For successful micronutrient fortification, different technical aspects need to be considered, such as the selection of appropriate food vehicles and fortificant, fortification levels, and adequate quality assurance and quality control. In addition, the chemical reactivity of the added micronutrients with each other and with components of the food matrix must be taken into account. Changes in sensory, physical, or chemical properties can lead to major problems with product stability and consumer acceptance; to avoid these issues, micronutrients are usually added in powder form as ingredients toward the end of the production processes. Different technologies are used, such as making a concentrated premix containing one or more micronutrients or encapsulation with vegetable oils, starches, gelatins, or other colloids to prevent sensory changes and micronutrient losses, as well as the extrusion for agglomeration and encapsulation. 113,114 Foods that have been successfully fortified in developing countries include staples such as grain flours and oils; condiments like salt, sugar, and sauces; and industrial products such as dairy products, noodles, and infant foods. Examples of clinical studies conducted in high-risk population groups to assess the efficacy and feasibility of micronutrient fortification of condiments and seasonings are summarized in Table 2. The overall outcome of such studies investigating the various food vehicles and micronutrients indicates the efficacy of the interventions and their nutritional benefits, and has also allowed the identification of the most suitable physicochemical forms of the fortificants, particularly in terms of bioavailability, stability, and organoleptic properties. A more detailed discussion on the bioavailability of key micronutrients and their efficacy in intervention studies, including consumption patterns, can be found in other articles devoted to that topic. The knowledge generated in these studies can be useful for improving existing fortification programs or for developing and implementing new ones. Technological considerations behind the different vehicles, which can be useful for their selection, are presented below. Soy and fish sauces have several advantages as vehicles for iron fortification. Of foremost importance is the fact that soy and fish sauces are widely consumed as part of the daily diet in countries where micronutrient deficiencies are highly prevalent. Thus, in Asian countries where dietary insufficiencies of iodine, iron, and vitamin A are common, fortification of soy or fish sauce is a suitable strategy. Since these condiments are added to many East Asian foods, the fortified micronutrients can reach most vulnerable populations. 115 The consumption of soy and fish sauces is high in countries like Vietnam, Cambodia, Thailand, and China, where these condiments are part of traditional Ann. N.Y. Acad. Sci (2015) 8 28 C 2015 New York Academy of Sciences. 19

13 Processing of fortified condiments and seasonings de Mejia et al. Table 2. Studies regarding the micronutrient fortification of condiments or seasonings Food vehicle Fortificant Country/area Outcome References Soy sauce Fish sauce Bouillon cubes Salt Iron (NaFeEDTA, ferrous sulfate plus citric acid) Iron (NaFeEDTA, ferrous sulfate plus citric acid); iodine NaFeEDTA; micronized ferric pyrophosphate; zinc; vitamin A Iodine; iron (encapsulated ferrous sulfate, ferric pyrophosphate); vitamin A Southeast Asia Southeast Asia Africa West and North Africa NaFeEDTA is the most appropriate iron source owing to its high effectiveness, absorption, and organoleptic properties, except for the study in Ref. 70, which supported ferrous sulfate High iron and iodine absorption and acceptable organoleptic properties indicated its usefulness in fortification programs Increased micronutrient intakes achieved in high-risk population subgroups Effective fortification strategy (highly stable microcapsules) in reducing the prevalence of iron-deficiency anemia, iodine deficiency, and vitamin A disorders in school-age children MSG Vitamin A; iron Philippines and Indonesia Improvement of serum vitamin A and iron reached using fortified MSG Curry Iron (NaFeEDTA) South Asia Significant reduction of prevalence of iron-defiencency anemia, due to its capacity to stimulate gastric acid secretion Seasoning Vitamin A; iron; Southeast Asia Multiple micronutrient fortified food powder zinc; iodine preparations were effective in improving mixes the levels of hemoglobin, serum retinol, and retinol-binding protein and facilitated the mobilization of iron storage in preschool children 68 70, 78, 83, 95, 105, , 67, 71, 76, 78, 83, 91, 95, 105, 117, 120 4, 42, , 45, 55, 60, 84 87, 91, 96, 100, , 114, 122, 123, 147, , 51, , 75, 124, , 77, 78, 93, 130 dishes. The intake of soy sauce becomes even higher as people alter their consumption patterns toward a more vegetarian diet, largely because of health concerns. 116 On the technical side, there are several advantages to using soy or fish sauce for micronutrient fortification. The liquid form allows for an even distribution of the fortificant, and the dark color and strong flavor can mask organoleptic changes that may result from addition of the fortificants. 105,115 A major problem in the iron fortification of fish and soy sauces has been the formation of a peptide precipitate. In this respect, NaFeEDTA is the only iron compound that does not precipitate fish sauce peptides, thus resulting in a sensory-acceptable product. Unfortunately, despite the superiority of NaFeEDTA as an iron fortificant, its industrial use has been somewhat limited by its high cost. 62 Most studies of soy and fish sauce fortification have used ferric sodium NaFeEDTA, minor studies have used ferrous sulfate, 71,116 and double fortification with iron and iodine have also been successfully achieved. 105 Bouillon cubes are used around the world as basic cooking ingredients. The use of bouillon cubes may be more common in developing areas than in Western countries, as they are relatively cheap ingredients. Because bouillon cubes may be widely consumed in areas where the population has increased risk for iron deficiency, their use as carriers for iron may be a preferred choice. A problem observed when conventional iron compounds were applied for the fortification of bouillon cubes was the appearance of an off-color in the resulting food product. A solution was to use iron in micronized ferric 20 Ann. N.Y. Acad. Sci (2015) 8 28 C 2015 New York Academy of Sciences.

14 de Mejia et al. Processing of fortified condiments and seasonings pyrophosphate form to avoid sensory problems. 62 Bouillon cubes have also been instrumental in certain countries in Africa for the delivery of iodine to needed populations by using iodine-fortified salt as a manufacturing ingredient. 104 Thus, in reality, bouillon cubes are indirectly fortified with micronutrients through the use of fortified ingredients. The possibility in modern times of multiple fortification of salt with more than iodine broadens the spectrum of nutrients that can be indirectly added to bouillon cubes. A thorough review of salt-iodization technology, including double and triple fortification with iodine, iron, and vitamin A, has been published by Mannar. 121 Unfortunately, depending on the iron source, the main challenges of double salt fortification with iodine and iron are a lower stability of iodine in the presence of iron, reduced iron bioavailability in the presence of iodine via an undetermined mechanism, and poor sensory quality. 122,123 Curry powder is another potential vehicle for iron fortification, particularly in countries in Asia and India where iron deficiency is highly prevalent and consumption of curry powder is part of their cultural traditions. 73,124,125 Experimentally, the most suitable iron fortificant for curry powder has been NaFeEDTA. 73, However, it is still necessary to explore other, less-expensive iron compounds to assure the success and sustainability of the programs. MSG is the vehicle that most closely fulfills the necessary conditions for fortification. Its production is highly centralized, and MSG may reach the largest proportion of target children and mothers with relatively little variation in per capita consumption. MSG is metabolized quickly in the body and, from the safety point of view, it is generally recognized as a safe food additive. 127 Several studies have corroborated MSG fortification with vitamin A as a feasible national fortification program. 50,51,112,126,128 However, in real life, implementation of programs of MSG fortification with vitamin A has encountered sensory and stability problems, in countries like the Philippines and Indonesia. Other iron fortificants that have been experimentally added to MSG include micronized ferric orthophosphate and zinc stearate coated ferrous sulfate. 112 Although the coated ferrous sulfate had reduced bioavailability relative to the uncoated form, 129 the coated fortified product showed acceptable color, taste, bioavailability, and particle size. Seasoning powders are single-dose packets containing multiple micronutrients in powder form. They are added manually to foods and dishes, usually at the table, and are targeted primarily to small children. The micronutrients fortified in these powders are mainly iodine, iron, vitamin A, and zinc. Seasoning powders can also reach the general population through their addition to instant noodles or rice. 93 In Thailand, where noodle consumption is common, a clinical trial showed the efficacy of a seasoning powder fortified with iron, zinc, iodine, and vitamin A on reducing the prevalence of anemia and biochemical deficiencies of micronutrients in primary school children. 130 Based on the effectiveness of this strategy, the use of seasoning powders for home use or fortification of complementary foods has been proposed as an intervention for improving micronutrient intake in children. 131 Impact of processing on fortification The main impact of processing on fortification is the potential loss and/or reduction of the levels of micronutrients added during the manufacture of the fortified product. In addition, the fortificant may react with components of the food matrix, leading to undesirable sensory alterations. The magnitude of such micronutrient losses and potential sensory changes will depend on the type of fortificant, the food vehicle, the type of process, storage temperature, transport conditions, and packaging materials employed. Depending on the process, factors that may affect the levels of micronutrients, or their potency in the case of vitamins, include thermal treatment steps, irradiation, oxidation, excessive light exposure, excessive moisture, and chemical interaction between the fortificant and food matrix components. Therefore, for a given process, overage levels of the fortificant need to be estimated so that extra amounts can be added to compensate for the losses during the process and storage of the finished product. Higher overages will in turn lead to higher production costs. In the case of the processing of micronutrient-fortified condiments and seasonings, a way to minimize the technological impact described above is to add the fortificant at the very end of the process and thus avoid deleterious processing steps. In addition, micronutrients can be protected by microencapsulation or the addition of antioxidants. However, this will also affect production costs. On the other hand, micronutrient losses Ann. N.Y. Acad. Sci (2015) 8 28 C 2015 New York Academy of Sciences. 21

15 Processing of fortified condiments and seasonings de Mejia et al. that may occur at home when cooking fortified foodsprovidedaspartofcommunitynutritionprograms have been prevented by delivering precooked foods by extrusion. 132 The addition of antioxidant vitamins or the exclusion of oxygen can also reduce vitamin losses. 133,134 However, microwave cooking does not appear to have a significant effect on vitamin potency or stability. 135 Safety considerations In addition to technical and economic considerations, safety of the intervention should also be an important component of any fortification program. 102, A primary concern is that the intake of the fortified micronutrient should not reach levels beyond pre-established maximum intakes know as tolerable upper intake levels (ULs). The UL is the highest average intake that will not pose a risk of adverse health effects in the population. ULs for key micronutrients added to condiments and seasonings are presented in Table 1. Of greatest concern with regard to potential toxicity is an excessive intake of vitamin A. Therefore, the maximum intake level of the fortified micronutrient should be estimated based on the maximum intake of the food vehicle by the population and the maximum level of the micronutrient in the fortified food. This also implies that, for a well-designed fortification program, food consumption data is needed. The risks of adverse effects caused by excessive micronutrient intakes have been described by the FAO/WHO 139 and the United States Food and Nutrition Board. 140 The excessive levels of the fortificant may also increase the possibility of undesirable sensory changes in the food and its stability; therefore, this is another aspect that need to be evaluated. 141 In addition, compliance with existing local or international fortification regulations will also contribute to the safety of the programs. Food standards established by the authorities usually indicate the safe levels of use and the legality of the fortification compounds and other ingredients used in the manufacturing process of a given vehicle. 142,143 Furthermore, regulations may also require labeling of the level of the fortified micronutrient in the food, thus assuring that such a level is compliant with safety standards. 144 All of these mean that monitoring compliance and enforcement of the fortification regulations should be important components of the fortification programs, not only for their efficacy but also for the safety of the interventions. 145 As such, they should also be part of an evaluation plan to assess the impact and effectiveness of the fortification programs. 146 Recommendations Key elements for an effective, safe, and sustainable program are the selection of a suitable food vehicle that is widely consumed by the target population, an appropriate fortification compound in terms of technical suitability and cost, monitoring and enforcement of relevant regulations, and consumer acceptance. Specific fortification guidelines to meet these requirements have been given by the WHO/FAO 62 as follows: (1) define the target population; (2) assess the intake and status of critical micronutrients; (3) select the food vehicle; (4) select the fortification compound; (5) determine the level of fortification; (6) establish the regulatory parameters; (7) estimate costs and secure necessary financial support; and (8) develop a monitoring and evaluation plan. From the processing point of view, new costeffective technologies need to be developed to reduce micronutrient losses and concurrent sensory changes during manufacturing and storage of fortified products, especially of the least stable micronutrients like vitamin A. A better understanding of the potential chemical or physical interactions between the fortificant and components of the food matrix used as a vehicle will facilitate the selection of both the vehicle and the fortificant. This may allow optimization of bioavailability and amelioration of concomitant sensory and quality issues. Therefore, this is an area that requires further study. Conclusions Condiments and seasonings are promising vehicles for micronutrient fortification. They are suitable for use in fortification programs, particularly for improving iron nutrition. Iron-fortified condiments have been proven, without unresolved significant technical difficulties, to be an effective strategy for combating iron deficiency in developing countries, especially in Africa and Southeast Asia. However, the addition of vitamin A to some condiments or seasonings like MSG has been more challenging because of poor stability of the fortificant and sensory alterations in the finished product. 22 Ann. N.Y. Acad. Sci (2015) 8 28 C 2015 New York Academy of Sciences.