Efeito de substratos de origem vegetal na elaboração de bebidas fermentadas

Abstract

The demand for non-dairy products has increased in recent years due to health-related aspects (allergy and/or intolerance to milk) and changes in eating habits, which has led the use of plant extracts to gain prominence in the development of new products. The aim of this work was to compare fermented milk, made from milk, with fermented beverages made from aqueous soy and rice extracts as alternatives to non-dairy products. To this end, three (03) treatments were developed, which were standardized in terms of total solids content (12% m/m), production and microorganisms (yogurt starter culture and Lactobacillus acidophilus), but which differed from each other in terms of the raw material used: Treatment 01 (T1 - control): milk, Treatment 02 (T2) aqueous soy extract and Treatment 03 (T3) aqueous rice extract. The different treatments were formulated for the analysis of proximate composition and physicochemical properties, instrumental analysis of color, viscosity, texture profile, syneresis and quantification of microorganisms. The treatments reached pH below 4.6 and acidity above 0.9 g of lactic acid/100 mL in 4.0 h of fermentation. Regarding the proximate composition, T2 had the highest protein content (p < 0.05) while T3 had the highest carbohydrate content (p < 0.05). During storage for 28 days, only pH values for T3 reduced (p<0.05), while acidity values for lactic acid remained constant for all treatments. In the color analysis, T1 and T3 differed from T2 in relation to L* and a*, tending to have greater luminosity and less green coloration (p<0.05); in turn, all treatments differed in relation to b* (p<0.05). Fermented beverages exhibited non-Newtonian fluid behavior. Regarding syneresis, T3 had the highest value at time 1, but significantly reduced throughout storage. T2 had the lowest syneresis value at the end of 28 days of storage. Regarding hardness, T2 had the highest value (p<0.05); while for adhesiveness it was T1 (p<0.05) and elasticity and cohesiveness did not differ between T1 and T2 (p>0.05). During storage, the enumeration of S. thermophilus at T3 significantly reduced (p<0.05); Lactobacillus sp reduced in treatments T1 and T3 (p<0.05), while the enumeration of total lactic acid bacteria remained viable throughout the shelf life. At the end of the period, all of them had total lactic acid bacteria counts in accordance with current legislation. The elaboration of fermented beverages from vegetable extracts can be technologically viable and be an alternative to traditional fermented milks.