Bioactive properties and evaluation of the prebiotic potential of cashew apple fiber using Bifidobacterium Lactis / Propriedades bioativas e avaliação do potencial prebiótico da fibra do pedúnculo de caju utilizando Bifidobacterium Lactis

Abstract

Agro-industrial byproducts possess biotechnological potential due to the presence of bioactive compounds. These have positive metabolic effects, such as the reduction of the risk of chronic diseases, inflammation, among others. The cashew apple is one of these byproducts and stands out for its levels of phenolic compounds, flavonoids and ascorbic acid, which provide high antioxidant capacity, in addition to being an excellent source of pectin, a dietary fiber that stimulates the growth of bifidobacteria. The aim of this study was to evaluate the bioactive characteristics and the in vitro prebiotic effect of processed cashew apple when subjected to Bifidobacterium lactis. Anaerobic fermentation was carried out in a shaker at 100 rpm, 37 °C for 24 hours, using processed cashew apple as the substrate, which was enriched with a nutrient solution containing mineral salts. The growth was estimated in colony-forming units (CFU/mL), during strategic intervals of fermentation times on selective bifidobacteria agar medium, and the medium's pH was monitored. The prebiotic fructooligosaccharide (FOS) was used as a control. The cashew apple showed bioactive properties, with ascorbic acid values of 4.58 ± 0.00 mg/100 g, total phenolic compounds of 366.85 ± 3.43 mg GAE/100 g, flavonoids of 85.03 ± 4.15 mg CE/100 g and antioxidant capacity of 17.78 ± 0.20 µM TEAC/g. Plate counts showed small white colonies and complete regular edges. The growth of bifidobacteria in FOS was 10 Log CFU/mL -1 after 24 hours of fermentation, while in the cashew apple the growth was 8.8 Log CFU mL -1 after 12 hours of fermentation, with a reduction in pH medium (pH 5.08) that left it slightly more acidic than the standard (pH 5.98). Thus, it can be inferred that the cashew apple presents important functional properties, with possible benefits to human health.

Nutritional value and health benefits of cashew apple

“…68 The cashew apple juice and fiber again act as prebiotics, contributing to gastrointestinal (GI) health. 69,70 Fiber has good implications for GI health, visceral fat/blood lipids, and the postprandial glucose response, 71,72 and as a result, aids in the prevention and management of diet-related diseases. Thus, the ability of cashew apples to serve as a functional food ingredient in promoting good health and development has been demonstrated, and all fears regarding their toxicity have been allayed.…”

“…This effect was attributed to the high fiber and bioactive compounds in the apple, which are well noted for promoting satiety and improving the metabolism of lipids and glucose in mice 68 . The cashew apple juice and fiber again act as prebiotics, contributing to gastrointestinal (GI) health 69,70 . Fiber has good implications for GI health, visceral fat/blood lipids, and the postprandial glucose response, 71,72 and as a result, aids in the prevention and management of diet‐related diseases.…”