Phenolic content, antioxidant activity and antiamylolytic activity of extracts obtained from bioprocessed pineapple and guava wastes

Abstract

-The relationship between phenolic content, antioxidant and antiamylolytic activities was investigated in Rhizopus oligosporus-mediated solid-state bioprocessing of pineapple and guava residues. Two different treatments of fruit residues mixed with soy flour (5g of soy flour and 5g of fruit residue; 1g of soy flour and 9g of fruit residue) were inoculated and incubated at 22 o C. Phenol rich extracts (non-concentrated and concentrated 10-fold by boiling) from day 2 and 10 were tested for their ability to inhibit alpha-amylase. In order to correlate the enzymatic inhibition with phenolic-linked antioxidant activity of the extracts, samples were evaluated for total phenolic content and free radical scavenging. Alpha-amylase inhibition was observed for all extracts, concentrated or not, with values ranging from 10.91% to 100% (complete inhibition). A direct correlation between the total phenolic content or the free radical scavenging activity and alpha-amylase inhibition was not found, demonstrating that such an inhibition could be caused by the presence of specific compounds, phenolic or not, rather than by the actual concentration of overall fruit phenolics.

Solid State Bioconversion for Producing Common Bean (<i>Phaseolus</i> <i>vulgaris</i> L.) Functional Flour with High Antioxidant Activity and Antihypertensive Potential

“…The cotyledons were cooked in acetic acid solution (pH 3.0) at 90˚C for 30 min, cooled at 25˚C for 3 h, inoculated with a suspension of R. oligosporus NRRL 2710 (1 × 10 6 spores/mL), and packed in perforated polyethylene bags (15 × 15 cm). Solid state bioconversion (SSB) was performed at 35˚C and fermentation times of 24,36,48,60,72,84,96 and 108 h. The resulting bioprocessed common bean cotyledons were dried (50˚C/8 h), cooled (25˚C) and milled (80-US mesh = 0.180 mm). Bioprocessed common bean flours from each fermentation time were blended with their corresponding milled seed coats, packed and kept at 4˚C in tightly sealed containers until use.…”

“…Cooked cotyledons of dehulled common beans were inoculated with a suspension of R. oligosporus NRRL 2710 (1 × 10 6 spores/mL), and incubated at 35˚C for times of 24,36,48,60, 72, 84, 96 and 108 h (after 108 h the cotyledons showed off odor). Flours from bioprocessed dehulled common bean from each incubation time were blended with their corresponding milled seed coats.…”

“…common beans, chickpeas, rice, oat, lupine, home bean, ground nut, wheat, corn/soybean [17][18][19][20][21]. The solid state bioconversion (SSB) would increase the phenolic content and antioxidant activity of fungal processed seeds and legumes which will enhance the potential health-relevant functionality [22][23][24].…”

Evaluation on antioxidative capacity, nephroprotective effect, and DNA damage protection of mixed low potassium vegetables and fruits juice powder in HEK-293 cells

“…Total Phenolics content was determined [20]. Briefly, 12.5 µL of the juice sample (mg MJP powder/mL water) was mixed with 50 µL of distilled water and then mixed with 12.5 µL Foilin-Ciocalteu reagent and allowed to stand for 5 min at room temperature.…”

Valorization of agroindustrial solid residues and residues from biofuel production chains by thermochemical conversion: a review, citing Brazil as a case study

“…During the ageing process phenolic compounds are extracted by lignin ethanolysis from the wooden casks. Sousa and Correia (2012) evaluated the phenolic content, the antioxidant activity and the antiamylolytic activity of extracts obtained from bioprocessed pineapple and guava wastes for producing biologically active products and enhance the value of fruit residues by providing a source of health relevant compounds. Phenolics are also used in the food industry as anti-microbial agents and food stabilizers (Martins et al, 2011).…”