Desenvolvimento de iogurte com atividade antioxidante utilizando polpa de Syzygium cumini L.

Abstract

Syzygium cumini (L.) is a plant belonging to the family Mirtaceae and known by the names of Indian black plum, Java plum, olive, black olives, jambolão, jamelão, janus, jamblon , jambolan, janman or oliveira. Its phenolic constituents, in leaves, barks and fruits, have pharmacological and phytotherapeutic activities, but this potential is underutilized. There is an increase on the demand for foods with functional properties, so the objective of this work was to elaborate yoghurts in full version and semi-skimmed version with the addition of Syzygium cumini’s pulp. Pilot tests were carried out to define the concentrations of pulp and milk to be used, from which it was defined to use 10% of S. cumini’s pulp and 20% of milk. The products were evaluated for physicochemical and microbiological parameters, the total phenolic concentration and the antioxidant capacity after 1.7, 14 and 21 days of the storage period of the product. The centesimal composition of the ready product and the pulp were determined. The sensorial acceptability of the elaborated products was evaluated after 7, 14 and 21 days of storage. Lactic bacteria added for fermentation remained viable for 21 days, with Streptococcus thermophilus being found in up to 10.95 log CFU g^-1in whole yogurt and 11.18 log CFU g^-1 in semi-skimmed yogurt. The population of Lactobacillus bulgaricus reached 6.05 log CFU g^-1 in whole yoghurt and 5.40 log CFU g^-1 in semi-skimmed yogurt. The elaborated yoghurts presented protein content of 4.29 g 100 g^-1 and 5.23 g 100 g^-1 for semi-skimmed and whole yogurt respectively. The ash content was 1.55 g 100 g^-1 for semi- skimmed yogurt and 0.97 g 100 g^-1 for the integral. The antioxidant capacity of the whole yogurt during storage ranged from 0.83 to 0.96 g of DPPH mg^-1 yogurt, while the semi- skimmed yogurt ranged from 0.67 to 1.00 g of DPPH mg^-1 yogurt. Total phenolic compounds were more abundant in whole yoghurt. According to the sensorial analysis, the whole yoghurt obtained the best evaluations in the parameters taste, texture and odor. In the attributes of color and acidity there was no significant difference between the two treatments (p <0.05). The overall acceptance of whole and semi-skimmed yogurt was greater after two weeks of storage. Both versions of yogurt produced were in accordance with the requirements of the legislation that regulates the production of dairy products in relation to the viability of lactic acid bacteria and the absence of contaminants during the storage days evaluated. Integral yogurt was more widely accepted for taste than semi-skimmed yogurt. The results indicate that the fruit of S. cumini can be used successfully in the production of yogurts as an alternative to the use of its antioxidant potential.