Things you must know about stevia applications in chocolate

Transcription

1 A natural solution for sugar and calorie reduction Things you must know about stevia applications in chocolate Roger Aidoo, Ph.D. and Suzanne Preddie-Atterby, M.Sc. Product Development, Chocolate Bayn Europe AB Bayn Europe AB Hornsgatan Stockholm Sweden Phone Fax info@bayn.se

2 Things you must know about stevia applications in chocolate Exploring the sweetening potential of EUREBA stevia based sweeteners in no-added-sugar milk chocolate Roger Aidoo, Ph.D. and Suzanne Preddie-Atterby, M.Sc., Product Development, Chocolate, Bayn Europe AB June, 2015 Abstract Rebaudioside A (RebA) is an alternative non-caloric sweetener and has been identified as the least bitter, and with the least persistent aftertaste among the major diterpenoid glycoside sweeteners present in stevia. To market stevia in the EU, two content conditions must be fulfilled: 1) The product must contain a minimum of 95% steviol glycosides and 2) The steviol glycosides must have a minimum of 75% Rebaudioside A or a minimum of 75% Stevioside or a minimum of 75% Rebaudioside + Stevioside. Steviol glycoside sweeteners containing high levels of Rebaudioside A are thus ranked high in sweetness and low in bitter aftertaste. Consequently, most new product development surrounding steviol glycoside sweetened food and beverage products has focused mainly on high purity Rebaudioside A products. There is large variation in the steviol glycoside composition of the different stevia sweeteners available in the market, which can impact the taste and cost of the final application. EUREBA 360 is a stevia product considered to have high levels of the lesser-known steviol glycosides. Findings however show that, combined with the right flavours, EUREBA 360 has great potential in the sweetening and flavouring of no-added-sugar milk chocolate formulations, providing a great tasty product at a much cheaper cost to the manufacturer. The insights gained from this research can be used by chocolate manufacturing companies as a starting point in optimizing a EUREBA 360 sweetened milk chocolate and also to implement in other choco late products. Key words Stevia, Rebaudioside A, EUREBA 360, sweetness, chocolate 1. Introduction Sweet taste predominantly produced by sugar plays an important role in food preferences. Dietary and health demands however continue to expand the market for intense sweeteners as alternatives to sucrose 1,2. The steviol glycosides Rebaudioside A and Stevioside are non-caloric natural products isolated from Stevia Rebaudiana Bertoni leaves and are widely used as intense sweeteners. Technical problems related to reducing a bitter or liquorice aftertaste, coupled with regulatory barriers previously prevented steviol glycoside sweeteners from becoming more widely marketed. For any high-intensity sweetener, natural or otherwise, in the end it boils down to two major factors: the cost to the manufacturer, and the taste. Rebaudioside A is available at moderate cost at 80% purity and at > 80% purity at high cost. Rebaudioside A is thus ranked high in sweetness and low in bitter aftertaste hence becoming the focus for most steviol glycoside sweetened products. There is however large variation in steviol glycoside composition of different stevia sweeteners. The differences are due to the combined effects of cultivar selection, farming technique, extraction and purification technique. Once the steviol glycosides have been purified, further blending with different high purity steviol glycosides, flavours and bulking can create a unique sweetener suitable for general or specific applications and in some instances at a better cost-inuse ratio. Cost and taste weigh equally heavy in a manufacturers choice of products. As a consequence the balance between cost and taste is a major concern that must be addressed in the stevia market. Consumer liking is the key to placing a product successfully page 2/7

3 on the market. This is especially true for chocolate, which is eaten more for pleasure than for nutrition. It is therefore useful to know which steviol glycoside composition works best in your chocolate product. Sugar-free and no-sugaradded chocolate products have generally been manufactured using either a single alternative sweetener or a combination of two alternative sweeteners. In the present study, the flavour profile and the consumer acceptability of stevia sweetened milk chocolate with different Rebaudioside A / steviol glycoside composition were investigated. With increased demand for natural intense sweeteners, this work serves both as a guide for food manufacturers seeking affordable but high quality steviol glycoside based sweeteners for product development, and to pre-inform the general public about BAYN s solutions for sugar and calorie reduction. 2. Method Sensory evaluation of the formulated milk chocolates was made by a Qualitative Descriptive Analysis (QDA) technique. The comparative analysis consisted of an Analysis of Variance (ANOVA) with the level of significance set at 5%. 3. Results 3.1 Sweetness and total flavour It is widely believed that consumer acceptability of different intense sweeteners depends on the similarity of their time profile to that of sucrose 3. Accordingly, work to improve sweeteners has been directed to mimicking sucrose and concerned with only one sense taste. The sweetness intensity of the three stevia products RebA 97, RebA 80 and EUREBA 360 was compared to that of sucrose at different concentrations (low, medium and high) and at different times (10s, 30s and 60s). All intense sweeteners showed a similar trend of decrease in sweetness intensity with increase in time (Fig 1). Although EUREBA 360 recorded lower sweetness intensity at all concentrations, its sweetness was not significantly (P>0.05) different from that of the other intense sweeteners regardless of the time of evaluation. Sweetness intensity /-',"-./"0.10" lc +-' = low,"234562"0.10" concentration mc 0-'1' = medium 7587"0.10" concentration hc = high concentration RebA 97 lc RebA 97 mc RebA 97 hc RebA 80 lc RebA 80 mc RebA 80 hc EUREBA 360 lc EUREBA 360 mc EUREBA 360 hc 20 Sucrose lc 10 Sucrose mc Sucrose hc 0 0!" #!" $!" %!" &!" 50 '!" 60 (!" Time (sec) Figure 1. Time-intensity profiles of RebA 97, RebA 80 and EUREBA 360 at different concentrations. page 3/7

4 Figure 2 compares the total flavour ratings of the intense sweeteners to sucrose at different times and at different concentrations. The total flavour also decreased with increase in time and increased with increase in concentration. At high concentration, sucrose recorded the highest total flavour when samples were evaluated at 10 sec. There was however no difference in total flavour ratings for all samples evaluated after 30 sec at high concentration (Fig. 2). Total flavour %/&,#-./#0.10# +/&,#234562#0.10# lc 1/&,#7587#0.10# = low concentration mc = medium concentration hc = high concentration RebA 97 lc RebA 97 mc RebA 97 hc RebA 80 lc RebA 80 mc RebA 80 hc EUREBA 360 lc EUREBA 360 mc EUREBA 360 hc Sucrose lc Sucrose mc Sucrose hc 0 "#!"# $"# %"# &"# '"# ("# Time (sec) Figure 2. Total flavour intensity ratings of RebA 97, RebA 80 and EUREBA 360 at different concentrations. 3.2 Sweetness equivalent estimation The relative sweetness of the three Rebaudioside A products equisweet to sucrose solutions prepared at 3-8g/100g concentrations was estimated. The results showed that, the higher the Rebaudioside A content of the product, the higher its relative sweetness to sucrose, with RebA 97, RebA 80 and EU- REBA 360 recording relative sweetness values of 376, 341 and 289 respectively at equisweet sucrose solution of 3g/100g (Fig 3). The relative sweetness of the intense sweeteners also decreased with increase in concentrations above 3g/100g equisweet sucrose solutions. The difference in relative sweetness of EUREBA 360 at the lowest and highest concentration was however of a lower margin compared to that of the other intense sweeteners, with EUREBA 360 recording only a 46% drop in relative sweetness from 3g/100g to 8g/100g equisweet sucrose solutions. page 4/7

5 400 Relative sweetness 350" " RebA 97 RebA 80 EUREBA %" 2 &" 3 '" 4 #" 5 (" 6 )" 7 *" 8 +" 9 Sucrose (g/100g) Figure 3. Relative sweetness estimation of RebA 97, RebA 80 and EUREBA 360 at different sucrose concentrations. Figure 4 shows the overall profile of the Rebaudioside A products compared to sucrose at equisweet concentration of 8g/100g. There was no significant difference in the total flavour and sweetness intensity for all three intense sweeteners. Sucrose however recorded a lower bitterness rating compared to the intense sweeteners. A similar trend was observed for liquorice aftertaste and off flavour attributes. Both natural and synthetic sweeteners have been described as having some bitter characters 4. Rebaudioside A often has a bitter aftertaste believed to be due to impurities which can impair or even change its sweetness perception at high concentrations 5. There was however no significant difference between the bitterness ratings of all three Rebaudioside A samples (Fig. 4) Intensity Total flavour Sweetness Bitterness Liquorice Off flavour EUREBA 360 RebA 80 RebA 97 Sucrose Figure 4. Graphical representation of sensory attributes of RebA 97, RebA 80 and EUREBA 360 at equivalent sucrose concentration of 8g/100g. page 5/7

6 $!"!!#,"!!# +"!!# *"!!# )"!!# ("!!# '"!!# &"!!# %"!!# $"!!#!"!!# 3.3 Flavouring and sensory profiling of no-added-sugar milk chocolate with EUREBA 360 In this work, sugar-free milk chocolate base containing dietary fibres and polyol and natural sugars from milk was sweetened and flavored using EUREBA 360 intense sweetener together with other flavoring agents. The sensory profile of the EURE- BA 360 sweetened milk chocolate base was compared to the unsweetened base to determine differences in sensory attributes brought by the intense sweetener. Different sweetener concentrations were first tested and then later different flavor combinations were formulated in the sweetened milk chocolate base to develop an EUREBA 360 sweetened milk chocolate with superior taste quality. One formulation was sweetened with EUREBA 360 and the other formulation was sweetened with EUREBA 360 in combination with assorted flavors. The profiles of the milk chocolate base (before sweetening), after sweetening with EUREBA 360, and after sweetening with EUREBA 360 together with selected flavors are shown in Fig 5. The milk chocolate base sweetened with EUREBA 360 recorded the highest sweetness intensity and sweet/bitter aftertaste. The milk chocolate base was rated high in bitterness which can be attributed to the bitterness in the cocoa mass used in producing the base. Addition of the assorted flavors however resulted in less bitterness, enhanced vanilla flavor and better sweetness. Panelists described the EUREBA 360 flavored product as having a good taste with enhanced vanilla flavor. 10,00 Sweetness 8,00 6,00 Aftertaste 4,00 Bitterness 2,00 0,00 Milk chocolate base + assorted flavours Cacao flavour Vanilla flavour Figure 5. Spider diagram showing comparison between sensory profiles of sweetened and unflavored sugar-free milk chocolate base. Figure 6 compares the EUREBA 360 sweetened milk chocolate base to conventional milk chocolate. The EUREBA 360 sweetened milk chocolate base showed a similar profile as the conventional milk chocolate. However, both samples (conventional milk chocolate and EUREBA 360 sweetened milk chocolate) were rated too sweet and with high sweet/bitter aftertaste (measured after 30s). Addition of the assorted flavors thus eliminated these shortfalls, thereby resulting in a product with the right sweetness, low sweet/bitter aftertaste and much enhanced vanilla flavor. All three products were however not statistically different from each other for all attributes and as such can be used interchangeably without consumers noticing differences in sensory perception. page 6/7

7 ($"!!# (!"!!# '"!!# &"!!# %"!!# $"!!#!"!!# Sweetness 12,00 10,00 8,00 6,00 Aftertaste 4,00 Bitterness 2,00 0,00 Conventional milk chocolate + assorted flavours Cacao flavour Vanilla flavour Figure 6. Spider diagram showing comparison between sensory profiles of EUREBA sweetened and flavored milk chocolate base and conventional milk chocolate 4. Conclusions The intense sweetener market is expanding and so is the influx of poor quality stevia. This is why BAYN continues to strive to ensure the best quality of stevia gets to you. The results showed that no significant difference existed between all Rebaudioside A products for total flavour, sweetness intensity and bitterness attributes at high concentrations. To this effect, BAYN S EUREBA 360 with an atypical steviol glycoside composition can find applications in sugar-free chocolates and chocolate products, providing a great tasty product at a much cheaper cost to the manufacturer than when using more wellknown steviol glycosides that are more costly. This is proven by the lack of any significant differences between EUREBA 360 sweetened and flavoured milk chocolate and conventional milk chocolate made with sucrose for all sensory attributes evaluated. References 1. Portmann, M & Kilcast, D. (1996). Psychophysical characterization of new sweeteners of commercial importance for the EC food industry. Food Chemistry 56 (3), Aidoo, R. P., Depypere, F., Afoakwa, E. O. & Dewettinck, K. (2013). Industrial manufacture of sugar-free chocolates Applicability of alternative sweeteners and carbohydrate polymers as raw materials in product development. Trends in Food Science and Technology, 32: Lawless, H. T. & Heymann, H. (1998). Sensory Evaluation of Food; Principles and Practices. Chapman & Hall, New York, USA. 4. Ott, D. B., Edwards, C. L. & Palmer, S. J. (1991). Perceived taste intensity and duration of nutritive and nonnutritive sweeteners in water using time-intensity (T-I) evaluations. Journal of Food Science, 2: Prakash, I., DuBois, G. E., King G. A. & Upreti, M. (2007). Rebaudioside A composition and method for purifying Rebaudioside A. U.S. Patent, Number A1. For more information please contact: Roger Aidoo, ra@bayn.se Suzanne Preddie-Atterby, spa@bayn.se Product Development, Chocolate Bayn Europe AB Hornsgatan Stockholm Sweden Phone Fax info@bayn.se