Firmness and biochemical composition of Shitake and Shimeji commercialized in natura and consumers' opinion survey

ABSTRACT Mushroom production has been growing in Brazil due to the culinary versatility of this food and its high nutritional value. However, few studies associating the aspects of its quality with the profile and preference of its consumers can be found in literature. Thus, in this study, we aimed to evaluate the firmness and biochemical composition of Shimeji and Shitake, as well as, the consumers’ profile and preference for purchasing these mushrooms. The mushrooms were characterized by firmness, protein and lipid content, total phenolic compounds, total flavonoids and antioxidation activity. In addition we carried out a survey on opinion of 308 mushroom consumers. The two mushrooms contain high protein content and low lipid content, and also expressive concentrations of bioactive compounds and antioxidant activity, suitable for these demanding functional food consumers. Shitake is approximately 4 times firmer than Shimeji and the highest levels for all analyzed biochemical attributes did not differ between the two studied mushrooms, except for protein content. The opinion survey indicated that young and adult women consume more mushrooms than men. Most of them buy mushrooms in supermarkets, and they are mostly higher educated people. No significant higher consumer preference for one of the two mushrooms analyzed was verified; however, most participants reported that they prioritize mushrooms which have characteristic aroma and flavor, smooth and juicy texture, being a convenient ingredient for a quick-cooking meal.

Effect of heating under pressure treatment on the antioxidant of quinoa

Heating under pressure treatment (HUP) is a method which can keep the complete form of quinoa grain after processing, which is beneficial to the development of subsequent products. The conditions for quinoa heating under pressure was optimized by response surface methodology to be: quinoa grains were regulated with adding 6.3% of pH 7.0 water and heated under 0.36 MPa pressure for 3–5 min, resulting in the predicted maxima of total phenolic content (TPC), Flavonoid and Saponin content were 313.21 mg GAE/100 g, 1.621 mg/g, and 16.78 mg/g and the values of OH Scavenging Rate, DPPH Scavenging Rate, ABST+ Scavenging Rate were 69.45, 91.73, and 52.38% separately. The content of flavonoid and saponin in the HUP samples were more than that in the boiled, baked, and extruded samples, which were close to that in raw quinoa sample, and meaning high retention of active phytochemicals and antioxidation activity in HUP quinoa. The hydroxyl radical scavenging rate is related to the content of polyphenol, flavonoid and saponin.

Optimization of Liquid Culture Condition of a Novel Fungus Hygrophoropsis sp. and Antioxidant Activity of Extracts

To evaluate pharmacological activities of a novel fungus Hygrophoropsis sp., the influence of aeration rate on the production of mycelial biomass, exopolysaccharides (EPS), and intrapolysaccharides (IPS) in the fungus Hygrophoropsis sp. was investigated. And the water extracts of cultured Hygrophoropsis sp. mycelia and the fermentation broth were analyzed for their antioxidation activity by using four different assay methods such as hydroxyl radical scavenging, superoxide radical scavenging, hydrogen peroxide scavenging, and reducing power. The Hygrophoropsis sp. was cultivated under various aeration rates in a 7 l bioreactor. The highest mycelial biomass (3.98 mg/mL) and IPS production (19.63 mg/g) were obtained at aeration rate 4.5 v.v.m. The results showed that Hygrophoropsis sp., in general, possesses a strong antioxidation activity in all assays tested. The deproteinized extracts had stronger antioxidation activity as compared to the un-deproteinized extracts by using superoxide radical scavenging, hydrogen peroxide scavenging, and reducing power. Besides, the un-deproteinized extracts had stronger antioxidation activity as compared to the deproteinized extracts by using hydroxyl radical scavenging. Thus, the polysaccharide extractions from the Hygrophoropsis sp. studied have antioxidant activities in vitro, which may be a good source of natural antioxidants or further investigation as potential natural antioxidants.

Characterization of Green and Yellow Papaya for Antioxidation and Glucose Uptake Stimulatory Activity in HepG2 Liver Cells

Objectives The long-term objective of present research is to evaluate papaya for anti-diabetic properties. The current objectives were (1) To determine polyphenolic contents and antioxidation activity of leaves, skin, pulp, and seeds of green and yellow papaya and (2) to evaluate their effects on glucose uptake in HepG2 liver cells. Methods The leaves, skin, pulp, and seeds samples were freeze dried and then extracted in water or 80% Methanol. The total phenolic contents of each extracted sample was determined using the Folin- Ciocalteu method. The antioxidation activity in each sample was determined using 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and Ferric ion reducing antioxidation power (FRAP) assays. Effect of each fraction on glucose uptake was determined using a fluorescent-tagged NBD-Glucose derivative. Results The concertation of polyphenols was highest in both water and methanol extracts of seeds from yellow papaya compared to that in seeds from green papaya. Leaves and skin fractions contained modest concentration of polyphenols whereas pulp contained the lowest concentration of polyphenols. FRAP assay indicates that both water and methanol extracts of leaves, skin, pulp, and seeds from yellow papaya exhibited higher antioxidation activity compared to that of green papaya. A similar antioxidation activity pattern was observed by DPPH assay. Leaves and skin from both green and yellow papaya showed modest to high antioxidation activity whereas pulp from both green and yellow papaya contained a low antioxidation activity. In contrast, green papaya extracts significantly stimulated glucose uptake in HepG2 liver cells compared to that of yellow papaya extracts. Both water and methanol extract of pulp from green papaya showed the greatest stimulation of glucose uptake followed by leaves and skin. Conclusions Although the seeds from yellow papaya contained highest concentration of polyphenols and exhibited highest antioxidation activity, pulp from green papaya showed significantly higher stimulation of glucose uptake in liver cells. Our data indicates that polyphenolic content and/or antioxidation activity in papaya may not be related to their glucose uptake stimulatory activity in liver cells. This study concludes that regular consumption of green papaya may be beneficial for preventing diabetes. Funding Sources Capacity Building Grant, USDA.