OPTIMIZATION OF LEVELS OF ARTIFICIAL SWEETENER FOR PREPARATION OF SUGAR FREE ICE-CREAM

Transcription

1 Asian J. Dairy & Food Res., 32 (4) : , 2013 AGRICULTURAL RESEARCH COMMUNICATION CENTRE / indianjournals.com OPTIMIZATION OF LEVELS OF ARTIFICIAL SWEETENER FOR PREPARATION OF SUGAR FREE ICE-CREAM K.R. Rathod,G.K. Londhe* and A.P. Naik Department of Animal Husbandry and Dairy Science, Marathwada Agricultural University, Parbhani , India Received: Accepted: ABSTRACT Sugar free ice-cream was prepared using different levels of aspartame, sorbitol and maltodextrin. The response variables considered were: flavour, sweetness, body and texture, colour and appearance and overall acceptability. A Central Composite Rotatable Design (CCRD) was used as experimental design. The Response Surface Methodology (RSM) was used to analyze and predict the optimum levels of artificial sweeteners for preparation of sugar free ice-cream. All model terms were significant in flavour at quadratic level for aspartame and maltodextrin except sorbitol whereas, in respect of sweetness, all the model terms were significant at linear level only. In respect of body and texture the model terms where significant at linear and quadratic level for maltodextrin only. But for colour and appearance the model term for aspartame and maltodextrin were significant at linear level except sorbitol. For overall acceptability the model terms at linear level were significant for aspartame and maltodextrin whereas, it is significant only for aspartame at quadratic level. The optimum levels of artificial sweeteners corresponded to 700 ppm aspartame, per cent sorbitol and 12 per cent maltodextrin on the basis of milk to obtain flavour score 9, sweetness score, body and texture, colour and appearance score 4.6 and overall acceptability score Key words : Aspartame, Buffalo milk, Maltodextrin, Sorbitol, Sugarfree ice-cream. INTRODUCTION Ice-cream represents one of the most dynamic sector of the dairy industry and has for two decades been the sector where the most value addition has taken place. Ice-cream and frozen deserts are delicate, delicious and nutritious food, liked by all the age groups and popular throughout the world. It is the source of important nutrients like fat, protein, carbohydrate, minerals and vitamins. It is stored under refrigerated conditions and consumed in frozen state, the distinction which no other foods can claim. The annual growth rate of ice-cream is per cent (Chenngowda, 2002 and Singh et al., 2005). The per capita consumption of ice-cream is very low at just 100 ml. per annum in India. On the contrary, consumption in U.S.A., New Zealand, Australia, Sweden and Italy is reported to be 22, 19, 17, 13 and 12 litter per annum, respectively (Anderson, 1997). With the modernization, the life style of mankind has greatly changed resulting into several risks for non-communicable diseases such as coronary heart diseases (CHD), stroke and diabetes. Diabetes mellitus is a condition in which the amount of glucose in the blood is too high. A survey conducted in in the city of Madras showed that the prevalence of diabetes mellitus in adults was 8.2 per cent which has increased to 11,6 per cent in (Ramchandran et al, 1997). In India diabetes was recognized as a disease more than a thousands years ago. The magnitude of the problem has been highlighted by the fact that India had about 30 million diabetic patients by the end of year According to recent WHO report, there is an increase in the diabetic people in developing countries as compared to that of developed countries and India will have largest number of people in the world with diabetes by the year By them, one out of every four of the worlds diabetics will be an Indian (Ramchandran, 2000). Now a days there is trend for health foods. According to recent survey conducted in India, on * Corresponding author s londheg@rediffmail.com

2 routine market research, the consumers have to cut back on ice-cream consumption because of fear of adverse impact on health (Ray 2000). A market survey in the USA also conformed a strong interest in low calorie ice-cream for a specific group of people will be the focus point of prominence for the Indian Ice cream manufactures in the coming decade. Ice-cream is mixture of fat, sugar and milk solid not fat together with added flavour and colour. So diabetic and people on restricted diets cannot consume ice--cream having normal ingredients. In the west, ice-cream and frozen desserts have been tried using aspartame as a sweetener with variety of bulki ng agent based on polydextrose, microcrystalline, cellulose etc. (Wolkstein, 1986). The products have lower energy content than standard products particularly if the sweetener and the bulking agent replace some of the milk solids as well as carbohydrates. MATERIALS AND METHODS Buffalo milk required for the study was obtained from Dairy Unit of Department of Animal H usbandry and Dairy Science, College of Agriculture, Marathwada Agricultural University, Parbhani. Raw milk was separated with the help of cream separator and standardized to 6.0 per cent fat and 9.0 per cent SNF. Artificial sweetener such as Aspartame, Maltodextrin were supplied by Himedia Laboratories Pvt. Ltd., Mumbai and Sorbitol 70 per cent supplied by Research Lab Fine Chemical Industries, Mumbai were used. Preparation of sugar free ice-cream: The standardized buffalo milk was heated to C and calculated quantity of skim milk powder, maltodextrin and sorbitol was mixed. The mixture was further heated to 68± 1 0 C for 30 min with continues stirring. At this temperature stabilizer was 0.3 %. The mixture was homogenized using two stage homogenizer. This mixture was cooled by dipping the container in tap water to about 30 C. Calculated quantity of aspartame was first dissolved in small quantity water and mixed with Vol. 32, No. 4, the mixture properly. This mixture was kept for ageing at C for 8 hours and finally churning was carried out in batch freezer maintained at -2 0 C. For each batch 2 lit. Ice-cream mix was used. After churning for minutes it is filled in paper cups of 100 ml. capacity and kept for hardening in deep freezer maintained at -18± 2 0 C temperature. A schematic flow diagram for the manufacture of sugar free icecream is given in Fig. 1. Sensory evaluation of sugar free ice-cream: The sensory evaluation of fresh samples of sugar free icecream was conducted by a panel of seven judges selected from the Department of Animal Husbandry and Dairy Science. To minimize the differences, the panelists were acquainted with the quality attributes and the defect generally associated with ice cream. Samples were evaluated for flavour (10), sweetness (5), body and texture (5), colour and appearance (5) using 25 points score card developed for this delicious sweet. The judges were also asked to rate the samples for overall acceptability with maximum score of 25. Experimental design and statistical analysis: Response Surface Methodology (RSM) was adopted in the experimental design and analysis (Myers and Montgomery, 2002). A Central Composite Rotatable Design (CCRD) of 3 variables at 3 levels was used to study the response patterns and to determine the optimum combinations of variables. The independent variables were aspartame, maltodextin and sorbitol (Table 1). The RSM was applied to the experimental data using a commercial statistical package, Design Expert software (Statease, Minneapolis, USA). A polynominal equation was fitted to the data to obtain a regression equation. The statistical significance of the terms in the regression equation was examined by analysis of variance (ANOVA). Response Surface Plots were generated with the same software and optimization of ingredient level was carried out. The models were used to interpret the effect of various levels of ingredient on the TABLE 1: Coded and uncoded values of variables and their levels. Independent variable Coded levels Aspartame (ppm) A Sorbitol (%) B Maltodextrine (%) C

3 268 ASIAN JOURNAL OF DAIRY & FOOD RESEARCH Buffalo milk Buffalo milk Standardization (6 % fat, 9 % SNF) Heating ( C) Sorbitol Mixing Dry blending of maltodextrine and SMP Pasteurization Addition of 0.3% (68± 1 0 C for 30 min.) Homoginization (2500 psi/500 psi) Cooling Dissolve aspartame in 5 times water at C. Ageing (Overnight) Addition of flavour (Vanilla) Churning / Freezing Filling in cups Hardrning (-18± 2 0 C for overnight) Store FIG. 1: Manufacture of sugar free ice-cream.

4 response i.e. flavour, sweetness, body and texture, colour and appearance and overall acceptability. Confirmatory experiments were carried out using optimal levels of independent variables obtained from optimization studies and compared with computed value using regression model. RESULTS AND DISCUSSION Responses for different levels of ingredients during preparation of sugar free ice-cream are shown in Table 2. ANOVA was conducted to assess the significant effects of the variables on the responses (Table 3). Second order polynominal models were regressed for all response at different level of ingredients (Table. 4). The models thus developed with coded variables are as follows. Flavour = *A* *B *C *A*B *A*C- 0.25*B*C *A * B * C 2 Sweetness = *A *B *C *A*B *A*C *BC -8.20*A * B * C 2 Body and texture = *A *B *C *A*B A*B *A*C *BC * A * B *C 2 Colour and appearance = *A *B *C *A*B *A*C*-0.009*B*C *A * B * C 2 Std. order Aspartame (ppm) Sorbitol (%) Maltodextrine (%) Vol. 32, No. 4, 2013 TABLE 2: Central Composite Rotatable Design Matrix and observed values of Response variables. Flavour (10) Sweetness (05) Body and texture (05) Colour and appearance (05) 269 Overall acceptability = * A * B *C *A*B *A*C -0.06*B*C 9.20*A B * C 2 To visualize the combined effect of two factors on the response, the response surface plots were generated Flavour : The maximum flavour score of the sugar free ice-cream was 9.0 while the minimum was 6.7 (Table. 2). The coefficient of determination R 2 was 0.89 and the predicted R 2 of 0.38 was in resonable agreement with the adjusted R 2 of 0.80 in case of flavour score (Table. 4). Data from Table 3 indicate that the lack of fit was not significant, (F cat > F tab ) confirming the significance of model at both 1 and 5 per cent. The model terms are significant i.e. the terms in the model have significant effect on the response. The model terms for aspartame and maltodextrin was highly significant in flavour score at linear as well as quadratic level, whereas, the effect of sorbitol is not significant at both levels. As the aspartame level increased, there was increase in flavour score at certain level, thereafter continues decline was observed at any given sorbitol level (Fig. 2a). At any given level of maltodextrin the flavour score increases as the level of aspartame increases up to certain level, thereafter it declines (Fig. 2b). But as function of maltodextrin and sorbitol, the flavour score increases as the level of maltodextrin increases (Fig. 2c). Overall acceptability (25)

5 270 ASIAN JOURNAL OF DAIRY & FOOD RESEARCH Flavour Design points belowpredicted value X1 = A: Aspar tame X2 = = F lavour (a) TABLE 3: Analysis of variance for the response variables. Flavour B: Sor bitol = Design-Expert Softwar e Fla vour Fla vour Design poin ts below pr edic ted value X1 = Actual Fac tor A: Aspar tame = Fla vo ur (b) C : M alto dextrin B : So r bitol (c) FIG.2: Response surface and contour plots showing effect of different variables on the flavour score (a) sorbitol vs aspartame (b) maltodextrin vs aspartame and (c) Maltodextrin vs sorbitol. Sweetness : The maximum sweetness attained during preparation of sugar free ice-cream was while minimum was 3.4. Data from Table 3 indicate that the lack of fit was significant (F cal < F cat ) confirming the significance of model at both 5 and

6 1 per cent. All the model terms where significant in sweetness at linear level whereas, non-significant at quadratic level (Table. 4) With increase in the level of aspartame, the sweetness score increases steadily and the increase was more pronounced at 700 ppm (Fig. 3a). Arora et.al.(2008) reported that in terms of sweetness perception, artificial sweetened Kalakand was found at par with the control and possessed the same desirable sweetness. With the increase in sorbitol level also increases the sweetness score sharply. As the level of maltodextrin increases, very slight increase in sweetness score was observed as compared to aspartame (Fig. 3b). Similar trend was observed by the interaction between sorbitol and maltodextrin level, as the level of sorbitol increases the sweetness score also increases whereas, light effect was observed with respect to maltodextrin (Fig. 3c). Body and texture : The maximum and minimum score for body and texture was found to be and 3 respectively (Table. 2). The model was found to be significant on the basis of lack of fit, the coefficient of regression R 2 was 0.89 indicating that the model developed was satisfactory. The model term for maltodextrin was highly significant in body and texture at linear and quadratic level whereas, for aspartame and sorbitol it is non significant at both level. With increase in sorbitol level, there was continues decrease in body and texture score at any Factor Vol. 32, No. 4, 2013 TABLE 4: Regression coefficient of different responses. 271 given level of aspartame. Similarly, increasing the level of aspartame also decreases the score (Fig. 4a) Arora et.al.(2008) reported the insufficient water binding capacity of artificial sweetener which resulted in a product with lower score for body and texture. With increasing the level of maltidextrin the body and texture score increases sharply at given level of aspartame. However, increasing level of aspartame shows no effect on score (Fig. 4b). Similar trend was observed in respect of maltodextrin and sorbitol. Increasing the level of maltodextrin increases the body and texture score at any given level of sorbitol. Whereas, no effect was observed for sorbitol (Fig. 4c). Colour and appearance : The maximum score for colour and appearance was 4.6 while minimum was 3.3 (Table. 2). The coefficient of determination R 2 was 0.97 which is higher than 0.85 suggested as minimum value by Henika (1982) for developing model for sensory data. The adequate precision value was calculated to be 22.2 which is higher than the table value of 4.00 required to develop satisfactory model. Moreover, the PREES value also small i.e 0.57 and hence the model fits well to analyze the data with design. All the model terms were significant in colour and appearance at linear level except for sorbitol. Whereas, all the model terms were non significant in colour and appearance at quadratic level. As the level of sorbitol increased, there was increase in colour and appearance score at constant Coefficient Flavour Sweetness Body and texture Colour and appearance Overall acceptability Intercept A- Aspartame 0.25** 0.19** ** 0.39* * B- Sorbitol ** C- maltodextrine 0.40** 0.08** 0.45* * 0.40* * 1.34* * A * * ** B C ** ** AB * * ** -0.35** AC * * 0.25 BC Adequate precision R Adjusted R Predicted R PRESS Model F value **Significant at 5 % level.

7 272 ASIAN JOURNAL OF DAIRY & FOOD RESEARCH Sweetness X2 = = S w e et n es s Sweetness 3.4 = S we et ne ss (a) A: As partame X2 = = = a 3.76 Sweetness (b) b X1 = B: Sor bitol = S we et ne ss X1 = = B o dy & Tex tu re FIG.3: Response surface and contour plots showing effect of different variables on the sweetness score (a) sorbitol vs aspartame (b) maltodextrin vs aspartame and (c) Maltodextrin vs sorbitol (c) B : Sorb itol FIG.4: Response surface and contour plots showing effect of different variables on the body and texture score (a) sorbitol vs aspartame (b) maltodextrin vs aspartame and (c) Maltodextrin vs sorbitol. c

8 Vol. 32, No. 4, Colour & App X2 = = Colour & App Overall Accp Design points belowpredicted value X2 = = Overa ll Accp a (a) Colour & App = Co lour & A pp Overall Accp Design points belowpredicted value = Overa ll Accp b (b) Colour & App X1 = = Co lo ur & A pp c FIG.5: Response surface and contour plots showing effect of different variables on the colour and appearance score (a) sorbitol vs aspartame (b) maltodextrin vs aspartame and (c) Maltodextrin vs sorbitol. Overall Accp Desi gn points below predicted value X1 = = Overa ll Accp (c) FIG. 6: Response surface and contour plots showing effect of different variables on the overall acceptability score (a) sorbitol vs aspartame (b) maltodextrin vs aspartame and (c) Maltodextrin vs sorbitol.

9 274 ASIAN JOURNAL OF DAIRY & FOOD RESEARCH aspartame level was observed and very slight effect was observed with increasing the level of aspartame (Fig. 5a). Arora et.al. (2008) reported that colour and appearance score were significant lower (P< 0.05) for artificial sweetened kalakand as compared to control. The colour and appearance score increased with increase in maltodextrin level at given level of aspartame (Fig. 5b). With increase in the level of sorbitol, colour and appearance score increased with increase in maltodextrine level (Fig 5c). Overall acceptability : The maximum and minimum score for overall acceptability was found to be 22.5 and 17.3 respectively (table. 2). The model was found to be significant on the basis of lack of fit, coefficient of determination and predicted R 2 as given in Table. 4. The model terms for aspartame were highly significant in overall acceptability at both linear as well as quadratic level and for maltodextrin only at linear level. In the two factor interaction, the interactions between the factors of aspartame and sorbitol were found significant effect on overall acceptability score. With increase in aspartame level the overall acceptability score increases up to certain limit and thereafter decreases at any given level of sorbitol. Similarly, increasing the level of sorbitol also increases the score (Fig. 6a). Increasing the level of maltodextrin shows pronounced effect on overall acceptability score at any given level of aspartame whereas, aspartame shows very negligible effect (Fig. 6b). Similar effect was observed in terms of maltodextrin and sorbitol. Increasing in the level of maltodextrin increases the overall acceptability score at any given level of sorbitol (Fig. 6c). Optimization : In order to optimize the ingredient levels during preparation of sugar free ice-cream, the consideration taken was maximization of flavour, sweetness, body and texture, colour and appearance and overall acceptability. Aspartame level was optimized at 700 ppm, sorbitol was optimized at 7 % level and maltodextrine was optimized at 12 % level. CONCLUSION The experimental data used for the optimization study were obtained using a CCRD. The RSM approach was employed to optimize the ingredients level for preparation of sugar free icecream utilizing flavour, sweetness, body and texture, colour and appearance and overall acceptability as response. When ice-cream was prepared using aspartame 300 to 700 ppm, sorbitol 7 to 11 % and maltodextine 8-12 % resulted in flavour score ranging from 6.7 to 9, sweetness 3.4 to, body and texture 3.0 to, colour and appearance and overall acceptability 17.3 to 22.5 REFERENCES Anderson, E.K. (1997). The Japanese market of ice-cream. Scondinavian Dairy Indus., 4 : Arora, S., Gawande, H., Narendra, K., Yarrakula, S., Singh, V.P., Sharma, V., Wadhwa, B.K., Tomer, S.K. and Sharma, G.S. (2008). Textural and structural properties of kalakand made with artificial sweetener Saccharin, Acesulfame-K, Sucralose and Aspartame. J. foods and Technol., 43 (3) : Chenngowda, H. (2002). Liquid milk marketing opportunities and trades. Indian Dairyman. 54 (2) : Henika, R.G. (1982). Use of response surface methodology in sensory evaluation. Food Technol., 36(11) : Myres. R.H. and Montgomery, D.C. (2002). response surface methodology process snd products optimization using design experiment. 2 nd Edn., John Wiley and Sons, Inc., USA, pp : Ramchandran, A. (2000). Hope for diabetic patients. In Preceeding of the scientific session APICON, Medicine Update. 10(1) : Ramchandran, A., Snchalatha, C., latha, E., Vijay, V. and Vishwanathan, M. (1997). Rising prevalence of NIDDM in an urban population area. Diabetologia, 40 : Ray, S.G. (2000). The big F, Outlook., June 12 : Singh, P.K., Mann, R.S. and Alok, JHA (2005). Proceeding of the nation workshop on development of low fat fibre enriched ice-cream scope of entrepreneurship industry held on at NDRI, karnel : Wolkstein. M. (1986). Dietic frozen dessert containing aspartame. US patent, US