ANA CLÁUDIA GUILHEN CARVALHO

Título da Dissertação:DESENVOLVIMENTO DE PRODUTOS ADOÇADOS COM REBAUDIOSIDEO-A E AVALIAÇÃO DE PROPRIEDADES FUNCIONAIS E SENSORIAIS

Orientador: PROF. DR. SILVIO CLÁUDIO DA COSTA

Data da Defesa: 17/04/2012

RESUMO GERAL

 INTRODUCTION: The leaves of the shrub Stevia rebaudiana (Bert.) Bertoni – a plant native to Paraguay - contain steviol glycosides (about 10 glycosides of steviol are often cited) which presents as main characteristic the high intensity of sweetness, being rebaudioside A (Reb-A) the most important. This substance as emerging as a new alternative of natural sweetener with quality in taste, free of calories, carbohydrates or fats, and is being rapidly gaining market especially after the fall of regulatory barriers imposed by the United States and Europe. In this work the performance of rebaudioside A present in new formulations of diet foods was compared with those of sucralose, an artificial sweetener that has excellent sensory profile and occupies 36% of the global market demand of high intensity sweeteners. The cranberry (Vaccinium macrocarpon Ait Ericaceae) is a fruit from the American family of berries, being rich in anthocyanins, flavonoids and proanthocyanidins, widely used as antioxidant, in the treatment of urinary infections, nonstick, with cancer-fighting properties, cardioprotective effects, hypoglycemic, and was used into the formulations of products developed in this work to incorporate functionality and/or nutraceutical properties.
OBJECTIVE: To develop formulations of diet jam and diet popsicle of strawberry enriched with cranberry and sweetened with Reb-A and sucralose to evaluate the properties regarding antioxidant activities, physical-chemistry characteristics, microbiological quality, and sensory evaluation.
MATERIAL AND METHODS: The physical-chemistry analyzes were made according to IAL (2005) methods. Microbiological analyzes followed the recommendations required by the RDC nº  12/2001 of ANVISA, according to the methods proposed by Silva (2007). Methodology for ascorbic acid quantification follows AOAC colorimetric protocols with modifications for jam analysis suggested by Oliveira, Prado (2010). The anthocyanins quantification was performed according to methodology proposed by Pineli; Moretti (2009), and analysis of total phenols acoording Morelli, Prado (2011). The methodology for antioxidant activity with DPPH followed the recommendations of Scherer, Godoy (2009) and sensory analysis was conducted with one hundred untrained participants following the 9-point hedonic scale and subjected to analysis of variance (ANOVA) followed by Tukey test (p <0.05%). RESULTS AND DISCUSSION: Physical-chemical - Jam F1 (humidity: 86.94%, total sugar:  5.03%, SS: 12.1 ° Brix, pH 3.66, protein: 1.31% citric acid: 1.6%, residue mineral fixed: 0.54%, fiber: 5.58%, ether extract, 0.59%, color: 33.94); Jam F2 (humidity: 84.86%, total sugar: 6.08%, SS: 13.3 ° Brix, pH 3.73, protein: 1.35% citric acid: 1.5%, ash: 0.54%, fiber: 6,64%, ether extract,  0.53%, color: 30.96); F1 ice cream (humidity: 84.9%, total sugar: 0.64%, SS: 12.5 ° Brix, pH 4.67, protein: 2.54%, citric acid, 1.27%, ash: 0, 9% fiber, 7.0% ether extract, 3.9%, color: 57.12); Ice Cream F2 (humidity: 84.9%, total sugars, 0.17%, SS: 10.9 ° Brix, pH 4.62, protein: 2.5%, citric acid, 1.10%, ash 0.9%, fiber: 8,15%, ether extract 3.4%, color: 53.59). Microbiological analyzes were all within normal limits for both jellies and for ice cream. The content of ascorbic acid (AA) was found to 325mg/100g jam F1, 527mg/100g jam F2, 432mg/100g for ice cream F1 and 386mg/100g for ice cream F2, confirming the data found by Pineli; Moretti (2009) in strawberry jam (AA content: 363.63 mg). Regarding the amount of monomeric anthocyanins (AM) were found 416mg (F1 jam), 483mg (jam F2), 154mg (ice cream F1) and 283mg/Kg-1 (ice cream F2). The concentration of anthocyanins found by Pineli; Moretti (2009) in strawberry jam was 257.97mg/kg-1 showing that the addition of cranberry juice to jam increased the concentration of AM. The total phenolic content found was 2.89 mg GAE jam F1, 3.08 mg GAE jam F2, 1.19 mg GAE ice cream F1, 1.15 mg GAE/g sample to the ice cream F2 and 16.14 mg GAE/g of sample in the juice concentrate (50º Brix) of cranberry. According to McKay; Blumberg (2007), cranberries contain a high amount of phenolic acids, ranging from 507 to 709mg GAE/100g. According to the work of Abby; Skrede; Wrolstad (2005), in the pulp of frozen strawberries, the variation of the concentration of total phenolics ranged from 230 to 341mg GAE/100g fresh weight and mashed, the range was 280 to 300 mg GAE/100g fresh weight. The antioxidant activity by DPPH (I%) varied with the concentration of the product: the higher the concentration, the greater the inhibiting power, which ranged from 25.9 to 33.42% (20mg/ml) for 83.7 to 94 % (100mg/mL) for jellies and 7.19% (20mg/ml) to 51.39% (100mg/mL) for ice cream. In the sensorial analysis, we interviewed 100 participants of both sexes, aged between 14 and 55 years. Comparing the two formulations - F1 and F2 can be observed that the sample with Reb-A was preferred for all attributes, however, the variables which have significant at 5% probability by Tukey's test (p <0.05) were the taste and purchase intent, to jam, and the taste, texture and purchase intent for the ice cream. In FLAVOR attribute to jam and ice cream with Reb-A, the scores ranged from seven (like moderately) and eight (liked), while for the jam and ice cream with sucralose were among five (or liked / or disliked) and six (like slightly).
CONCLUSIONS: According to the physico-chemical and sensory characteristics of diet jam and ice cream of strawberry plus cranberry, one can conclude that the product showed a good option to the use of strawberry and alternative supply of products of low-calorie, good source of antioxidants for a specific audience, such as diabetic and obese. The inclusion of cranberry juice products added functional properties, especially in relation to vitamin C, AM and antioxidant activity by DPPH. Jellies and ice cream showed similar characteristics to each other (F1/F2) and good acceptance, and the best option was used sweetener Reb-A used alone (100%). Both jellies and ice cream showed no no contamination, proving that they were prepared in good sanitary conditions.
KEY WORDS: Edulcorant, Stevia; Cranberry; Ices, Jelly

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