Consumers are increasingly seeking

http://dx.doi.org/10.1094/cfw-58-2-0055 2013 AACC International, Inc. S. Bellaio, S. Kappeler, and E. Zamprogna Rosenfeld Bühler AG, Uzwil, Switzerland M. Jacobs Bühler GmbH, Braunschweig, Germany Consumers are increasingly seeking natural food products that are both tasty and healthy. The question is how can we, the food industry, successfully meet these demands? Germination is a natural and traditional method that can be used to improve the nutritional, functional, and sensory properties of grains such as pulses and cereals. Pulses are a particularly rich source of vegetable proteins, dietary fibers, vitamins, and minerals, but their nutritional value is limited by the presence of antinutrients that reduce digestibility and micronutrient bioavailability. Germination is a powerful natural process that reduces the antinutrient content in pulses while substantially augmenting their nutrient content. In many countries, the germination process traditionally has been performed at a household level, but an industrial process has recently been developed to apply the advantages of natural germination at an industrial scale and enable the development of innovative commercial food products. In this process, grains are partially germinated under controlled conditions and then stabilized by drying with hot air to extend the shelf life of the products. The chemical properties of several partially germinated grain products have been extensively analyzed, and analysis has shown a significant reduction in antinutrient content, as well as a significant increase in micronutrient bioavailability. Moreover, the process greatly increases the simple sugar content, which can add a pleasant sweet flavor note to food products. Baking trials have also shown that the addition of partially germinated wheat flour to pan bread greatly improves functional properties such as loaf volume and shelf life. This article describes how the partial germination process can be used at an industrial scale to create fully natural ingredients with high nutritional value and improved functional properties for novel food formulations. Partial Germination of Pulses Pulses include dried peas, beans, lentils, chickpeas, and other seeds from plants in the legume family. Consumers like them because they are a naturally rich source of vegetable protein, soluble and insoluble fibers, vitamins, and minerals. Some of the key minerals found in pulses are iron, potassium, magnesium, and zinc; key vitamins are those from the B group, including folate (folic acid), thiamin, and niacin. Additionally, pulses are not high in fat. Unfortunately, these crops are underexploited at an industrial scale, and they are rarely used as ingredients in processed food products due to nutritional and sensory issues. The presence of indigestible carbohydrates such as ROF (raffinose family of oligosaccharides) can cause digestive discomfort for some people due to gas production and bloating. Furthermore, the presence of natural antinutrients, such as trypsin inhibitors and phytic acid, reduces the bioavailability of several micronutrients that are present in pulses, both for humans and animals. Trypsin inhibitors are peptides that reduce trypsin activity and, thus, protein digestion in many animals, including humans. Phytic acid, on the other hand, binds with important minerals, such as calcium, magnesium, iron, and zinc, preventing them from being absorbed in the intestine. Phytic acid also may chelate niacin, making it unavailable. Finally, the strong flavor associated with pulse ingredients, which consumers may be unaccustomed to, makes it challenging for food manufacturers to include pulses in food formulations such as bakery products, pastas, and extruded snacks. Significant addition of pulse flours to food products that do not normally contain them are often identified by consumers as an off-flavor that is generally described as beany or green. CEREAL FOODS WORLD / 55

Germination can be used to improve the nutritional value and sensory properties of pulses. The process has been used for hundreds of years at a household level in many countries, and its nutritional benefits have been documented extensively in the scientific literature (3). During germination, natural enzymes that degrade antinutrients such as phytic acid and trypsin inhibitors are expressed, increasing their vitamin content and the bioavailability of some minerals. Enzymes are also able to degrade ROF into shorter carbohydrates such as mono- and disaccharides. This has two main effects: reduction of digestive discomfort caused by the presence of ROF and development of a sweet flavor note in germinated pulses, which is usually desirable and may facilitate the acceptance of these ingredients in processed food products. The basic germination process consists of steeping pulses in water until they reach the moisture content needed to initiate germination, after which the steeping water is drained and the pulses are allowed to germinate under cool, humid conditions. Some challenges must be overcome to perform this process at an industrial scale. First, germination is a batch process that requires a long timespan. It can be a costly process, therefore, if not optimized properly. Moreover, process conditions must be constantly and precisely monitored and controlled to standardize the properties of the final product and assure good quality is maintained. Finally, after the germination phase, the grains are still wet and usually have a moisture content of 30 50% (wb), which complicates the logistics of product transport and storage. To overcome these issues, an innovative process technology (Pargem, Bühler AG) has been developed in which grains such as pulses are partially germinated under controlled conditions and stabilized through drying with hot air to extend product shelf life. Dry partially germinated pulses can be used as is or processed further (e.g., as flour) to be integrated into novel food formulations (Fig. 1). Effects of Partial Germination of Pulses Nutritional Value. We have examined the effects of partial germination on several types of pulses, including brown chickpeas, mung beans, and pigeon peas. Table I summarizes the results for micronutrients, macronutrients, and antinutrients in partially germinated flour made from brown chickpea splits. Figure 2 shows the degradation of ROF over the course of processing. With the degradation of ROF there is a concomitant increase in the content of the simple sugar fructose. Antinutrients, such as trypsin inhibitors and phytic acid, are reduced through enzymatic degradation. The effects of these reductions are evidenced by the increase in both vitamins, such as niacin (vitamin B 3 ), and dialyzable minerals, such as iron, zinc, and calcium (Figs. 3 and 4). Experiments to assess the effects of the industrial germination process on nutritional value have also been performed with other types of pulses and resulted in similar trends in improved nutritional quality in these types of products. Fig. 1. Brown chickpea products: raw grain; partially germinated fresh grain; and partially germinated processed whole grain, splits, and flour. (Copyright Fig. 2. Reduction of flatulence factor ROF (raffinose family of oligosaccharides) in partially germinated brown chickpea splits flour following short and long process treatments. (Copyright Bühler AG, Uzwil, Switzerland) Fig. 3. Vitamin contents of partially germinated brown chickpea splits flour following long process treatment. RDI = recommended daily intake. (Copyright Fig. 4. Dialyzable iron content of partially germinated brown chickpea splits flour following short and long process treatments. (Copyright Bühler AG, Uzwil, Switzerland) Table I. Changes in nutrient content of partially germinated brown chickpea splits flour Quantity in Nongerminated % Change in Partially Component Flour (mg/100 g, dm) Germinated Flour Oligosaccharide Raffinose family, flatulence factor 7.58 70 Antinutritional factor Trypsin inhibitor activity 5,072 U/g dm 30 Phytic acid 854 12 Mineral Dialyzable iron 0.065 +150 Dialyzable zinc 0.55 +60 Dialyzable calcium 22.50 +35 Vitamin Thiamine (B 1 ) 0.15 +500 Niacin (B 3 ) 0.90 +100 Folic acid (B 9 ) 0.07 +30 Riboflavin (B 2 ) 0.10 +40 Ascorbic acid (C) 1.50 +25 Simple sugar Fructose 100 +220 56 / MARCH APRIL 2013, VOL. 58, NO. 2

Sensory and Functional Properties. We have examined the dehulling of brown chickpeas, mung beans, and pigeon peas and found them to be significantly easier to dehull and split after partial germination treatment (1). The process also influences the sensory properties of pulses. The previously discussed increase in simple sugars such as fructose may explain the increased sweetness that was observed. A sensory assessment performed with a trained panel (6) confirmed that cooked partially germinated splits of brown chickpeas had a significantly sweeter flavor compared with a nongerminated reference sample. Cooking trials have also shown that the germination process can influence the cooking properties of pulses, including cooking time and dispersed solids. In addition, results of the cooking trials showed that if the process parameters are not accurately monitored and optimized, germinated pulses may require an undesirable longer cooking time (1). Careful control of the quality of the steeping water is a key measure to control this phenomenon. A more systematic and comprehensive examination of the use of partially germinated pea flours in food products with improved nutrition and flavor attributes is being performed in collaboration with Alberta Agriculture and Rural Development, the Canadian International Grains Institute, the University of Manitoba, Agriculture and Agri-Food Canada, and the Pulse Crops (Canada) Association. Yellow peas processed at the Bühler pilot plant in Switzerland (Fig. 5) will be milled into flour for this project and analyzed for their physicochemical and functional properties, including vitamin content, mineral bioavailability, antinutrient content, protein quality, and in vitro digestibility. These flours also will be integrated in pilot food products such as pastas, extruded snacks, and baked goods that will be assessed for their functional and sensory properties. Partial Germination of Cereals and Pseudocereals Germination has been shown to improve the properties of other grains, such as cereals and pseudocereals, as well (2,4). In an industrial process similar to the one described for pulses, cereals and pseudocereals have been partially germinated under controlled conditions and stabilized by drying with hot air. As shown in Figure 6, cereals such as wheat can be partially germinated and dried and then milled into a flour that can be utilized in novel food products. As with pulses, the process for cereals and pseudocereals can improve the nutritional, functional, and sensory properties of the raw materials. Experimental trials with different cereals and pseudocereals have resulted in partially germinated flours that exhibit higher vitamin (e.g., folic acid), dialyzable mineral (e.g., calcium and iron), and dietary fiber contents. The content of sugars such as glucose, maltose, and sucrose has also been found to increase during this process and is probably responsible for the sweet flavor note of these ingredients. Flavor can be further modified by adjusting the parameters of the final drying step to confer a maltedroasted-nutty flavor that can be exploited for applications in processed food products. Another characteristic of partially germinated and dried grains is that they can be used to produce flours that are naturally enriched with enzymes. As has already been mentioned, natural enzymes, such as amylases and proteases, that are present in the grain are expressed during germination. These enzymes can confer improved functional properties to grain flours and augment the properties of the baked products derived from them. Application of Partially Germinated Wheat Flour in Pan Bread To assess the effect of partially germinated wheat flours in bakery products, pan breads were formulated and baked using raw (untreated) or partially germinated wheat flour according to the following formula: 100% flour (14% wb), water according to farinograph, 2% yeast, and 2% salt. The ingredients were mixed, and the optimal kneading procedure for each of the single flours was determined in preliminary tests. Doughs were placed in plastic bins, covered with a plastic sheet, and left to rest at ambient temperature for 60 min. After bulk proofing, 600 g pieces were weighed and molded with a long roller. Molded pieces were placed in baking pans, transferred to the fermentation chamber, and left for 50 min at 32 C and 80% RH. The bread loaves were baked at 230 C for 45 min. The volume of each baked bread loaf was measured with a volume scanner (VolScan Profiler, Stable Micro Systems). For firmness measurements, each loaf was cut into Fig. 5. A, Detail of partially germinated yellow pea production; B, full view of pilot plant during processing of partially germinated wheat. (Copyright Fig. 6. Wheat products: raw grain; partially germinated fresh grain; and partially germinated processed whole grain and flour. (Copyright Bühler AG, Uzwil, Switzerland) CEREAL FOODS WORLD / 57

3 4 slices (each 30 mm thick). Each slice was then compressed by 50% twice in a series at a velocity of 50 mm/min (Texture Analyzer XT2i, Stable Micro Systems). The maximum force applied was taken as a measure of crumb firmness. For comparison, a loaf containing commercial enzymes added to untreated flour was also baked and analyzed. As shown in Figures 7 and 8, the bread containing partially germinated wheat had a higher specific volume than the reference bread containing nongerminated wheat. The loaf containing partially germinated wheat also had lower firmness during staling, which corresponds to a longer shelf life for the product. These positive effects are mainly due to the natural enzymes expressed during the germination process. The presence of these enzymes may help reduce the quantity of commercial enzymes that needs to added to bread formulations as well, or even eliminate their need, thereby improving consumer acceptance and creating a cleaner label. Further baking trials were done with lower levels of partially germinated flour, i.e., 20 and 50%, incorporated in the bread formula. These trials showed that it is possible to improve specific volume and firmness during staling using lower levels of partially germinated wheat flour. The nutritional value of pan breads made with partially germinated wheat flour has not yet been studied. However, based on related studies (2,5), we would expect a significant improvement in the content of micronutrients such as vitamins. Further studies are currently being conducted on the application of several partially germinated grains (e.g., wheat, rice, oat, rye, and corn) and their flours in processed foods such as extruded products, pastas, and cookies. Application of Partially Germinated Products in Feed and Pet Foods Partially germinated pulses and cereals could potentially be used as natural ingredients in feed and pet food products as well. The nutritional benefits of their applications in human foods, such as improved digestibility and improved micronutrient contents, could be exploited to produce innovative and nutritious animal food products. For example, partially germinated pulses could be added to feed products to increase protein content, improve digestibility, increase nutrient contents (e.g., phosphorous and soluble fibers), and reduce antinutrient contents (e.g., trypsin inhibitors and phytic acid). The natural enzymes present in partially germinated ingredients could also contribute to reduced use of the commercial enzymes normally integrated into feed formulations. In-depth research is currently being performed to investigate this application of partially germinated grains. Industrial Production and Technology The technological solution to partial germination on an industrial scale consists of using a batch unit with a capacity of up to 14 tons. The unit successively performs all the steps needed for the partial germination and stabilization of grains (steeping, germination, and drying) in the same processing chamber. The equipment is easily transportable and is designed for straightforward integration and commissioning. It is built in a modular design consisting of two modules for the process chamber and aeration, which are integrated in standard containers, and two modules for utilities management and the automation system. Additionally, the unit contains an independent loading and unloading system to feed the grain into the process chamber and to discharge the finished product from the process. All processing steps are performed in a span of 3 4 days. Conclusions The availability of partially germinated and stabilized grains, such as pulses, cereals, and pseudocereals, at an industrial scale dramatically expands the potential for the integration of these novel ingredients into the food and feed markets and helps to meet increasing consumer demands for natural food products that are also healthy and tasty. The industrial process described here can be applied to a wide range of grains and seeds and provides an interesting differentiation opportunity for many players in the food and feed industries, e.g., millers and processors of cereals and pulses, bakeries, producers of extrudates and pellets, food and feed ingredient manufacturers, maltsters, brewers, and others. Acknowledgments The analytic work on brown chickpeas, mung beans, and pigeon peas was performed by CSRI/CFTRI under a consultancy Fig. 7. Appearance and specific volumes of pan bread loaves produced using semiwhite nongerminated (reference) wheat flour without and with commercial enzymes added and semiwhite partially germinated wheat flour. (Copyright Fig. 8. Changes in firmness during staling of pan breads produced using semiwhite nongerminated (reference) wheat flour without and with commercial enzymes added and semiwhite partially germinated wheat flour. (Copyright 58 / MARCH APRIL 2013, VOL. 58, NO. 2

assignment from Bühler. We thank the scientists at CSRI/CFTRI who were involved in the project for their great work and support. We also thank Rosemary Kern Graf, who studied the effect of Pargem wheat flour on pan bread during her internship at Bühler. We acknowledge the funders of the project on partially germinated pea flour: Alberta Crop Industry Development Fund Ltd., Alberta Innovates Bio Solutions, and Alberta Pulse Growers Commission. References 1. Bellaio, S., Zamprogna Rosenfeld, E., Mane, D., and Jacobs, M. Novel process based on partial germination to enhance milling yield and nutritional properties of pulses. Cereal Foods World 56(Suppl.):A30, 2011. 2. Hefni, M., and Witthöft, C. M. Increasing the folate content in Egyptian baladi bread using germinated wheat flour. LWT Food Sci Technol. 44:706, 2011. 3. Kadam, S. S., and Salunkhe, D. K. Handbook of World Food Legumes: Nutritional Chemistry, Processing Technology, and Utilization. CRC Press, Boca Raton, FL, 1989. 4. Omary, M. B., Fong, C., Rothschild, J., and Finney, P. Effects of germination on the nutritional profile of gluten-free cereals and pseudocereals: A review. Cereal Chem. 89:1, 2012. 5. Rakĉeyeva, T. Biologically activated grain in wheat bread technology. Ph.D. thesis. Latvia University of Agriculture, Jelgava, Latvia, 2006. 6. Zamprogna Rosenfeld, E., Bellaio, S., Mane, D., and Jacobs, M. A new family of healthy, safe, and convenient food products based on partial germination of pulses. Cereal Foods World 56(Suppl.):A71, 2011. Stefania Bellaio has been working with Bühler for three years as a project manager in the R&D Department of the Grain Processing Division. She has managed and supported projects related to improving the nutritional and functional properties of grains, with a special focus on pulses. Stefania has a master s degree in chemical engineering for sustainable development from Padua University, Italy, and is a member of AACC International. Stefania can be reached at stefania.bellaio@buhlergroup.com. Stefan Kappeler joined Bühler a year ago as a project manager in the R&D department. He provides expert input concerning biochemical and food safety issues. Stefan has a Ph.D. degree in technical sciences from the Swiss Federal Institute of Technology, ETH Zurich, Switzerland. Eliana Zamprogna Rosenfeld has been working with Bühler for 10 years. Since joining the company in 2003, she has fulfilled several functions in the field of R&D and is currently head of R&D for the Grain Processing Division. In this role, she coordinates the strategic innovation portfolio of the division, which is targeted toward improving grain processing technologies with respect to nutritional added value, sustainability, food safety, and process intelligence. Eliana received her Ph.D. degree in chemical engineering from the University of Padova, Italy. During her studies, she also worked as a visiting researcher at the University of California, Santa Barbara, USA, for two years. Michael Jacobs earned his Dipl.-Ing. (FH) degree in process engineering from the University of Applied Science TFH Berlin in 2004. He interned at Bühler in 2007 as a project manager in R&D. He is currently product manager of malting and is responsible for product planning and execution throughout the product lifecycle, including gathering and prioritizing products and customer requirements, defining product vision, and working closely with universities and R&D, sales, and support departments to ensure revenue and customer satisfaction goals are met. CEREAL FOODS WORLD / 59