Insect residues as an alternative and promising source for the extraction of chitin and chitosan.

This work aimed to obtain and characterize chitin and chitosan extracted from the rearing residues of Tenebrio molitor, Zophobas morio, and Blaptica dubia insects in different growth stages in the same rearing cycles chitin and chitosan yielded 11.21 %-20.89 % and 6.26 %-7.07 %, respectively. The deacetylation degrees of chitosan ranged from 75.75 %-89.21 %, and the solubilities from 69.88 %-94.39 %. Infrared spectroscopy corroborated the acquisition of chitin and chitosan and can be used as a semi-quantitative technique for determining the degree of chitosan deacetylation. The X-ray diffraction profiles revealed the presence of α-chitin, and the relative crystalline indices ranged from 65.9 %-89.2 %. Typical TG profiles with two thermal events are observed for chitin and chitosan samples with different residue contents from the extraction procedure. The chitosan solutions exhibited pseudoplastic behavior, with apparent viscosities ranging from 195.96 to 249.86 mPa.s. The characterization results of the biopolymers extracted from insect residues were similar to those obtained from conventional sources. The growth stage influenced the chitin yield and crystallinity index. The results of this study reinforce the feasibility of using alternative sources of chitin and chitosan, providing the use of waste from insect farms and contributing to sustainability and a circular economy.

Resveratrol-Loaded Attalea funifera Oil Organogel Nanoparticles: A Potential Nanocarrier against A375 Human Melanoma Cells.

This study aimed to evaluate Attalea funifera seed oil with or without resveratrol entrapped in organogel nanoparticles in vitro against A375 human melanoma tumor cells. Organogel nanoparticles with seed oil (SON) or with resveratrol entrapped in the seed oil (RSON) formed functional organogel nanoparticles that showed a particle size <100 nm, polydispersity index <0.3, negative zeta potential, and maintenance of electrical conductivity. The resveratrol entrapment efficiency in RSON was 99 ± 1%. The seed oil and SON showed no cytotoxicity against human non-tumor cells or tumor cells. Resveratrol at 50 µg/mL was cytotoxic for non-tumor cells, and was cytotoxic for tumor cells at 25 µg/mL. Resveratrol entrapped in RSON showed a decrease in cytotoxicity against non-tumor cells and cytotoxic against tumor cells at 50 µg/mL. Thus, SON is a potential new platform for the delivery of resveratrol with selective cytotoxic activity in the treatment of melanoma.

Long-term cryopreservation of Lentinus crinitus strains by wheat grain technique.

Lentinus crinitus (Basidiomycota: Polyporales) is a saprophytic fungus with biotechnological importance described more than 20 years ago. However, there are few studies on the long-term preservation of this basidiomycete. Cryopreservation is a long-term storage technique that reduces the metabolic activity of microorganisms, but its success depends on the adjustment of the freezing process, the cryoprotectants, and the protective substrates for each species. This study aimed to assess the mycelial viability and genetic stability of L. crinitus strains cryopreserved at -86 °C for two years by the wheat grain technique using different cryoprotectants and freezing methods. Three strains of L. crinitus (U9-1, U13-5, and U15-12) were subjected to different concentrations and types of cryoprotectants (dimethyl sulfoxide, glycerol, glucose, and sucrose), freezing methods such as immediate freezing from 25 to -86 °C and progressing freezing from 25 to -86 °C in a freezing container with isopropyl alcohol to control the rate of cell freezing at -1 °C min-1, protective substrate (wheat grain and 2% malt extract agar), and cryopreservation period (1, 6, 12, and 24 months). After thawing, samples were evaluated for mycelial viability, time to mycelial recovery, mycelial stability, and genetic stability of the fungus. All techniques achieved effective cryopreservation at -86 °C, mainly with the wheat grain technique. All cryoprotectants (3.5% glycerol, 1.5% dimethyl sulfoxide, 25% sucrose, and 5% glucose), freezing methods (immediate and gradual), and protective substrate (wheat grain and malt extract agar) were effective for cryopreservation of the three L.crinitus strains in an ultra-low temperature freezer for two years. Mycelial viability, mycelial stability, and genetic stability of the fungus were not affected after two-year cryopreservation, evidencing the robustness of the long-term cryopreservation technique and the fungus.

Antimicrobial activity of Annona muricata leaf oleoresin.

Bioactive compounds extracted from plants such as antimicrobials have attracted the attention of consumers and the food industry. This study aimed to determine the antimicrobial activity and chemical composition of Annona muricata leaf oleoresin obtained by supercritical CO2 extraction. The oleoresin was obtained by supercritical CO2 extraction and the chemical identification by gas chromatography coupled to mass spectrometry. Antimicrobial activity was evaluated by broth microdilution method against 14 foodborne fungi and bacteria. The oleoresin major chemical class was phytosterols (22.7%) and the major compounds were γ-sitosterol (15.7%), α-tocopherol (13.7%), phytol (13.1%), and hexadecanoic acid (11.5%). Minimum inhibitory concentration against bacteria ranged from 0.0025 to 0.010 mg mL-1. The oleoresin had high bactericidal activity against all bacteria, mainly Enterobacter cloacae and Pseudomonas aeruginosa with 0.005 mg mL-1 minimum bactericidal concentration. However, it had low fungicidal activity. The leaf oleoresin of A. muricata has promising applications in food, cosmetic, and pharmaceutical industries.

Syrah Grape Skin Residues Has Potential as Source of Antioxidant and Anti-Microbial Bioactive Compounds.

In this study, we evaluated the effects of ultrasound-assisted extraction (UAE) under different time-temperature conditions on the content of bioactive compounds, antioxidant and antimicrobial activities of Syrah grape skin residue. The application of UAE showed a positive effect on the extraction of total flavonoids, and a negative effect on total polyphenols. The temperature of 40 °C and 60 °C without the UAE caused an increase of 260% and 287% of the total polyphenols, respectively. Nineteen individually bioactive compounds were quantified. The anthocyanin concentration (malvidin-3,5-di-O-glucoside 118.8-324.5 mg/100 g) showed high variation, to a lesser extent for phenolic acids, flavonoids, flavonols, procyanidins and stilbenes due to the UAE process. The Syrah grape skin residue has a high concentration of total phenolic compounds of 196-733.7 mg·GAE/100 g and a total flavonoid content of 9.8-40.0 mg·QE/100 g. The results of free radical scavenging activity (16.0-48.7 mg/100 mL, as EC50) and its inhibition of microbial growth (0.16 mg/mL, as EC50 for S. aureus, and 0.04 mg/mL, as EC50 for E. coli) by grape skin extract (UAE 40:20) indicate high antioxidant and antibacterial activity. It was concluded that the use of ultrasound needs further analysis for its application in this context, as it has shown deleterious effects on some compounds of interest. Syrah grape skin residue has potential as a source of bioactive antioxidants, antimicrobial activity and for use as a functional food ingredient.

Effect of Drying Methods on Bioactive Compounds and Antioxidant Capacity in Grape Skin Residues from the New Hybrid Variety "BRS Magna".

The effects of the drying process using the conventional oven and freeze-drying on the thermogravimetric profile, proximate composition, color parameters, individual bioactive compounds, and antioxidant activity in the grape residue (skin) were evaluated. Twenty individual phenolic compounds were identified, where a variation in concentration was observed for flavonols, stilbenes, phenolic acids, flavonoids, procyanidins, and particularly anthocyanins (malvidin-3,5-di-O-glucoside of 253.2-536.9 mg/kg) due to the drying process. Drying in a conventional oven caused a decrease of 23% of the total polyphenols. The skin of the BRS magna grape has a high concentration of total phenolic content of 489.5-148.3 mg.GAE/100 g, total anthocyanin content of 124.9-260.1 mg.CE/100 g, and total flavonoid content of 12.7-26.0 mg.QE/100 g. The results of free radical scavenging activity (1.26-4.91 µg/mL, as EC50) and ferric reducing antioxidant power (82.93-184.10 µmol/g of skin as equivalent to Fe2SO4) indicate high antioxidant activity, independently of the drying process applied. It was concluded that, if the application is directed to anthocyanin compounds, the use of lyophilization is recommended. On the other hand, if the interest is in bioactive compounds that exert antioxidant activity, conventional oven-drying can be used.

Soy ß-conglycinin (7S globulin) reduces plasma and liver cholesterol in rats fed hypercholesterolemic diet.

The aim of this study was to examine the comparative hypocholesterolemic effect of soybean 7S fraction in rats fed a high-cholesterol diet. Soybean 7S globulin (ß-conglycinin) was administered orally once a day to rats, and the effects were measured after 28 days. Wistar rats were divided into four groups: standard diet (STD) (casein alone), hypercholesterolemic (HC) diet (STD plus 1 g/100 g cholesterol and 0.5 g/100 g cholic acid), HC+7S(1) diet (HC diet plus 200 mg of 7S/kg of body weight/day), and HC+7S(2) diet (HC diet plus 300 mg of 7S/kg of body weight/day). Food intake, weight gain, animals' growth, and feeding efficiency ratio were similar among the STD and three HC groups, indicating that these parameters were not affected by treatments. Animals that had received different doses of soybean 7S globulin had lower total cholesterol (TC), triglycerides (TG), and low-density lipoprotein (LDL)/high-density lipoprotein (HDL) ratio in serum and lower levels of hepatic TC and TG than those fed only the HC diet. The atherogenic indexes of HC+7S(1) and HC+7S(2) groups were 40% and 55% lower than that of the HC group, respectively. The results showed that the oral daily administration of ß-conglycinin in the diet to HC rats, at between 1.85% and 2.75% of total ingested protein, promotes the reduction of TC, LDL-cholesterol, and TG and an increase in HDL-cholesterol in the plasma, besides a small but significant reduction in cholesterol and TG levels in the liver of the animals as well as a reduced atherogenic index.