ABSTRACT
Fruta-do-lobo (Solanum lycocarpum St. Hill) is a native fruit commonly used in Brazilian folk medicine as a hypoglycemic agent. These properties are attributed to their starch, mainly its resistant fraction. Resistant starch has shown to increases the growth of Bifidobacterium and Lactobacillus in the gut, even though not being selective for these strains. In this scenario, this study aimed to investigate the potential prebiotic activity of fruta-do-lobo starch (FLS). FLS showed around 30% of resistant starch and their prebiotic potential was evaluated with five probiotic strains L. acidophilus (LA3 and LA5), L. casei (LC01) and B. animalis (BB12) and B. lactis (BLC1) in a concentration range of 1.0-2.0% of starch. In a preliminary screening, we evaluated, during 48 h, the viability of the starch with promoting growth agent. An increase in the growth of the probiotic strains tested was observed. We also evaluated the microorganism's metabolic activity by assessing the short-chain fatty acid (SCFA) production, using the best starch growth promotion conditions (2% of FLS and strains BLC1, LA5, and LC01). As expected, MRS and lactose were preferentially metabolized by BLC1, with the highest growth rates: 0.231 and 0.224 h-1, respectively. However, for this strain, the FLS growth rate (0.222 h-1) was 65% higher than FOS (0.144 h-1). Also, for LA5 FLS promoted higher growth (0.150 h-1) than FOS (0.135 h-1). Additionally, FLS promoted acetate production. These data are promising and indicate that FLS may have prebiotic potential and more studies need to be done with pathogenic microorganisms.
Subject(s)
Probiotics , Solanum , Bifidobacterium , Brazil , StarchABSTRACT
In this study we evaluated the proximate composition of two Solanaceae fruits from Brazilian Cerrado, their mineral content, volatile organic compounds (VOCs), phenolic compounds profile, and antioxidant capacity employing Oxygen Radical Absorbance Capacity (ORAC) assay, for each part of the fruits (pulp, peel and seeds). Our results showed that the pulp has a high moisture content (74.62-85.40â¯g/100â¯g) and soluble fiber (1.29-2.06â¯g/100â¯g) content, and low fat, protein, and ash content. The peel exhibited high levels of carbohydrates and total fibers (6.55-11.39 and 12.35-13.12â¯g/100â¯g, respectively), while the seed presented high content of fat, protein, and insoluble fiber (10.14-12.62, 9.14-13.24 and 19.84-23.15â¯g/100â¯g). Potassium is the main mineral found in both fruits. It is the first time that the carbohydrate profile, volatile components, and phenolic compounds of the fruta-do-lobo and juá-açu are reported. 1-Kestose (GF2) and nystose (GF3) were found in both fruits. The main VOCs of juá-açu were esters, while in fruta-do-lobo, aldehydes were the major components. UPLC-Q-ToF fraction analysis of juá-açu and fruta-do-lobo revealed 24 phenolic compounds, most being hydroxycinnamic acids derivatives in juá-açu, and chlorogenic acids in fruta-do-lobo. The antioxidant capacity (ORAC) of the fruits ranged from 1.35 to 11.51⯵mol TE/100â¯mL of extract. These results indicate that Solanum genus can be interesting for the Brazilian fruit market, and that it has potential to be exploited for agroindustry for diversification of fruit products.
