POST-ACIDIFICATION AND EVALUATION OF ANTHOCYANINS STABILITY AND ANTIOXIDAN ACTIVITY IN AÇAI FERMENTED MILK AND YOGURTS (Euterpe oleracea Mart.)

Abstract

-This study evaluated the post-acidification, stability of anthocyanins and antioxidant activity in açai yogurts and fermented milks for 28 days of cold storage. For the determination of post-acidification and stability of the functional properties of açai yogurt (IA) and fermented milks (LFA), products stored at 4°C were evaluated on day 0 and every 7 days for pH, titratable acidity in lactic acid, instrumental color, anthocyanins and antioxidant activity by the DPPH free radical method. Acidification of both food matrixes was more evident between days 0 and 7 of evaluation. IA presented reduction in parameter L *, while chromaticity a * and b * of IA and LFA increased as the Açai pulp content increased; however, considering the evaluation period, it was found increase in L * and b * relating to anthocyanin degradation. Anthocyanins, as well as the antioxidant activity of IA and LFA, showed an increase in their values as the pulp content increased, but their concentrations reduced at the end of the storage period. IA and LFA can be considered excellent sources of antioxidants, being alternative to individuals not used to the consumption of fruits and vegetables. Index terms: Dairy products, functional foods, native fruits, Amazon. ESTUDO DE PÓS-ACIDIFICAÇÃO E AVALIAÇÃO DA ESTABILIDADE DE ANTOCIANINAS E ATIVIDADE ANTIOXIDANTE EM IOGURTES E LEITES FERMENTADOS DE AÇAÍ (Euterpe oleracea Mart.)RESUMO -Neste trabalho foi avaliada a pós-acidificação, a estabilidade das antocianinas e da atividade antioxidante em iogurtes e leites fermentados de açaí durante 28 dias de armazenamento refrigerado. Para determinação da pós-acidificação, assim como da estabilidade das propriedades funcionais dos iogurtes (IA) e leites fermentados (LFA) de açaí, os produtos armazenados a 4 ºC, foram avaliados no dia 0 e a cada 7 dias, quanto ao pH, acidez titulável em ácido lático, cor instrumental, antocianinas e atividade antioxidante pelo método do radical livre DPPH. A acidificação de ambas as matrizes alimentares foram mais evidentes entre os dias 0 e 7 de avaliação. Os IA apesentaram redução no parâmetro L*, enquanto que as cromaticidade a* e b* dos IA e LFA aumentaram seus valores, à medida que o teor de polpa de açaí foi aumentado, entretanto considerando o período de avaliação, verificou-se aumento de L* e b* relacionando-se as degradações nas antocianinas. As antocianinas, assim como a atividade antioxidante dos IA e LFA mostraram aumento em seus valores conforme os teores de polpa foram aumentados, porém reduziram suas concentrações ao fim do período de armazenamento. Os IA e LFA, podem ser considerados excelentes fontes de substâncias antioxidantes, sendo alternativa a indivíduos não habituados ao consumo de frutas e legumes. Termos para indexação: Produtos lácteos, alimentos funcionais, frutos nativos, Amazônia.

Short communication: Effect of purple corn pigment on change of anthocyanin composition and unsaturated fatty acids during milk storage

“…The intermolecular co-pigmentation of anthocyanins had a sterically compact structure, increasing the protective intramolecular mechanism to become more stable (Eiro and Heinonen, 2002). These results agreed with the observation of Campos et al (2017) in which the level of anthocyanins in milk decreased by approximately 40% at 28 d of storage.…”

Impact of post fermentation cooling patterns on fatty acid profile, lipid oxidation and antioxidant features of cow and buffalo milk set yoghurt

“…Variation in DPPH free radical scavenging activity was observed during the long term ripening of cheese [35]. Campos et al [38] conducted studies on antioxidant capacity of yogurt for the storage period of 28 days and DPPH antiradical activity assay was used to find anti-oxidative activity of samples. The results showed that antioxidant capacity of yogurt decreased in the storage phase.…”

Preliminary Screening of Growth and Viability of 10 Strains of Bifidobacterium spp.: Effect of Media Composition

“…Despite the low pH values that may affect the viability of tested microbes, bifidobacteria in our study survived in concentrations >5 log CFU/mL as stated previously. Regarding the shelf stability of samples analyzed, the post-acidification study is an important step since it reflects metabolic behavior of microbes used [35]. As seen in Figure 2, all samples analyzed followed an almost linear pattern within the storage period, except the DSM 20104 strain in reconstituted milk.…”