Bioprospecção de compostos bioativos e funcionalidade do cladódio de mandacaru (Cereus jamacaru DC.): avaliação do efeito prebiótico, do potencial nutricional e viabilidade tecnológica no processamento de iogurte caprino

Abstract

In this study, was elaborated and characterized regarding the technological, nutritional, bioactive and prebiotic properties of the Mandacaru cladode Flour (MF), as well as its technological feasibility in the processing of goat yogurt. MF was evaluated in terms of microbiological, technological, physical, physical-chemical parameters, sugar and organic acid profiles and antioxidant potential. In addition, digested and lyophilized FM was evaluated for prebiotic properties, based on measures of stimulating effects on the growth and metabolism of Lactobacillus strains, as well as on the composition and metabolic activity of the human colonic microbiota in vitro. Finally, four formulations of goat Yogurt were made with Tamarind Jelly (TJ) and FM at different concentrations: CY (Control Yogurt, without FM and GT); YJ (Yoghurt added 10% TJ); IJF1% (Yogurt added with 10% TJ and 1% MF) and the formulation YJF2% (Yogurt added with 10% TJ and 2% MF), which were characterized after the refrigerated storage times of 1, 14 and 28 days at (4 + 1 °C). Yogurts were evaluated for technological, physical, physical-chemical, microbiological and antioxidant aspects. MF proved to be a product with no contamination by possible pathogens. The granulometric profile showed a particle size between 20-60 um. MF showed low water activity (0.423) and moisture content, high ash, protein and total carbohydrates and low lipid content. This matrix proved to be an excellent source of insoluble dietary fiber and minerals, especially calcium. In the HPLC chromatography method, glucose was identified as the predominant sugar and four organic acids, with emphasis on malic acid, followed by citric acid. Eighteen phenolic compounds were detected, highlighting relevant amounts of kaempferol, myricetin and resveratrol. The total flavonoid content represented 1.18% of the total phenolics present. FM showed positive probiotic scores and viable Lactobacillus cell counts in different culture media, which ranged from > 6.2 (time 0) – 7.24 (time 48) log CFU/mL, resulting in a decrease in pH, increased production of lactic acid and short-chain fatty acids (acetic and propionic) and consumption of sugars. MF caused a change in the relative abundance of gram-positive microorganisms to the detriment of gram-negative microorganisms evaluated after 48 h of colonic fermentation. The prebiotic indices were positive after 24 and 48 h of in vitro colonic fermentation, demonstrating an intense metabolic activity, with an increase in SCFA production, pH decrease and sugar consumption. As for goat yogurts, there was a reduction in syneresis and apparent viscosity during storage, with greater reductions for the formulations added with TJ and MF. During storage, there was a reduction in pH and sugar content with concomitant increase in acidity. After 28 days of cold storage, an increase in the count of Streptococcus thermophilus and Lactobacillus bulgaricus was observed in the YJF2% formulation. The results of the total contents of phenolics, flavonoids and ABTS were higher in the YJF2% formulation, after 28 days of storage. The aforementioned data demonstrate that Cereus jamacaru DC. is an excellent food matrix for flour development. Furthermore, it is suggested that MF is a potentially prebiotic ingredient and it was found that the development of goat yoghurt added to MF was presented as a nutritious option for practical applications in the goat dairy industry.