Low-temperature plasma modification, structural characterization and anti-diabetic activity of an apricot pectic polysaccharide.

To fully research the anti-diabetic activity of apricot polysaccharide, low temperature plasma (LTP) was used to modify apricot polysaccharide. The modified polysaccharide was isolated and purified using column chromatography. It was found that LTP modification can significantly improve the α-glucosidase glucosidase inhibition rate of apricot polysaccharides. The isolated fraction FAPP-2D with HG domain showed excellent anti-diabetic activity in insulin resistance model in L6 cell. We found that FAPP-2D increased the ADP/ATP ratio and inhibited PKA phosphorylation, activating the LKB1-AMPK pathway. Moreover, FAPP-2D activated AMPK-PGC1α pathway, which could stimulated mitochondrial production and regulate energy metabolism, promoting GLUT4 protein transport to achieve an anti-diabetic effect. The Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy data showed that the LTP modification could increase the CH bond content while decreasing the C-O-C/C-O bond content, indicating that LTP destroyed the C-O-C/C-O bond, which enhanced the anti-diabetes activity of the modified apricot pectin polysaccharide. Our findings could pave the way for the molecular exploitation of apricot polysaccharides and the application of low-temperature plasma.

Green extraction of carotenoids from apricot flesh by ultrasound assisted corn oil extraction: Optimization, identification, and application.

The valorization of waste apricot flesh (WAF) can solve environmental and economic problems, and also meets the demand for natural pigments. Therefore, the aim of this paper was to recover carotenoids from WAF, to determine the type and content of carotenoids in the extracts and to explore the potential of the extracts for food industry applications. The extraction conditions were optimized. The total carotenoids content (TCC) was 42.75 mg/100 g dried weight under the optimized conditions: Time: 60 min, Temperature: 41.53℃, Power: 200 W, Liquid to solid (LS) ratio: 0.10 g/mL. The highest content of carotenoids in the corn oil extracts (COE) was phytoene. Color of COE under high temperature was investigated. Carotenoids in the COE were degraded at high temperatures. The a* of fries fried by COE was 7.31 times higher than that of corn oil. This study provides guidance for the green recovery of carotenoids and valorization of WAF.

Proteomic analysis reveals the mechanism of green regulation in garlic puree induced by purple light stress.

Greening is an undesirable appearance in garlic puree during processing. Our previous study indicated that purple light could induce the greening changes in garlic. In order to investigate the mechanism of green regulation in garlic puree, purple light-induced greening and nongreening garlic puree were used as materials to investigate the differentially expressed proteins (DEPs) by sodium dodecyl-sulfate polyacrylamide gel electrophoresis and data-independent acquisition (DIA) technology. The results showed that a total of 186 DEPs were detected by DIA, with 73 DEPs were up-regulated in greening garlic puree and 113 of them were down-regulated in greening garlic puree. Most DEPs were belonged to 20 functional categories, and mainly participated in post-translational modification and transport of proteins, molecular chaperones (12.93%) and signal transduction mechanisms (10.20%), energy production and transformation (6.80%), carbohydrate transport and metabolism (5.44%) and amino acid transport and metabolism (4.08%), indicating that the biological metabolic pathway, metabolic direction, and metabolic strength efficiency significantly changed in garlic puree after greening. Besides, the physiological and biochemical experiments showed that purple light significantly induced the γ-glutathione transpeptidase activity and prompted the conversion of thiosulfinate into garlic green pigment. This study explained the general molecular mechanism of greening changes of garlic puree in response to purple light. Practical Application Greening is an undesirable appearance in garlic puree during processing, which deteriorate the qualities of garlic. This study provides a comprehensive understanding of green regulation in garlic puree based on proteomics analysis.

Enhanced extraction of bioactive natural products using ultrasound-assisted aqueous two-phase system: Application to flavonoids extraction from jujube peels.

The ultrasound-assisted aqueous two-phase extraction (UA-ATPE) was employed to develop an effective technique for the extraction of flavonoids from jujube peels (JPs). The extraction conditions were further optimized as K2HPO4 35% (w/w), ethanol 20% (w/w), solid-liquid ratio 1:30 g/mL (w/v), ultrasonic power 200 W, and extraction time 50 min. Moreover, rutin, quercetin 3-ß-d-glucoside, and kaempferol-3-O-rutinosid were identified as the main flavonoids by UPLC-MS/MS. Finally, the extraction mechanism of UA-ATPE was explored, which is salting out effect, hydrogen bonding, van der Waals force, and ultrasound promoted the mass transfer of solvent to cells of JPs, then extraction behavior occurred. The mechanical destruction of JPs cells by ultrasound also further accelerated the release of flavonoids. Flavonoids were captured by W/W emulsion in the bottom phase and distributed to the top phase. Overall, this study proposes a green and clean method, UA-ATPE, to extract flavonoids from JPs, while revealing the mechanism of UA-ATPE.

Preparation of Monascus-fermented ginkgo seeds: optimization of fermentation parameters and evaluation of bioactivity.

In this study, a high monacolin K yield was achieved through solid-state fermentation of Ginkgo biloba seeds. Monascus purpureus suspension made from red yeast rice was used as spore inoculum. Fermentation conditions in solid-state fermentation were optimized using response surface methodology, and the optimal conditions for the maximum monacolin K yield (17.71 ± 1.57 mg/g) were 0.22% ammonium sulfate, 0.34% ammonium chloride, 0.05% magnesium sulfate, fermentation time of 12 days, inoculation volume of 11%, and temperature of 27 °C. The total phenolic content of Monascus-fermented ginkgo seeds attained 9.67 mg GAE/g, 4.88-fold higher than that of unfermented ginkgo seeds. The scavenging abilities of DPPH and ABTS free radicals increased to 9.79 mg TE/g and 13.92 mg TE/g, respectively. These findings highlight the importance of investigating the optimal fermentation conditions for maximum monacolin K yield and the utilization value of ginkgo seed as fermentation substrate for higher bioactivities. Supplementary Information: The online version contains supplementary material available at 10.1007/s10068-022-01078-z.

Age-dependent alteration in metabolism of vitamin B6 , neurotransmitters, and amino acids after 4'-O-methylpyridoxine administration in rats.

4'-O-methylpyridoxine (MPN), a recognized antivitamin B6 compound, is a potentially poisonous substance found in Ginkgo biloba L. In this work, the effects of MPN on the metabolism of vitamin B6 , neurotransmitters, and amino acids were compared in the plasma and brain of young and adult rats under various administration times. Results showed that the contents of MPN residues in the plasma and brain of young rats were 12.72 and 14.76 µM higher than adult rats, respectively. Moreover, the levels of 5-hydroxytryptamine and dopamine in the brain of young rats have decreased by 13.78% and 7.19%, respectively, compared with the control group, at 2 h after MPN administration. Furthermore, the principal component analysis revealed that MPN was an important contributor to the amino acid composition in the brain of young rats. These results suggest that age may lead to different toxic effects of MPN. PRACTICAL APPLICATION: 4'-O-methylpyridoxine is primarily responsible for poisoning due to overconsumption of Ginkgo biloba seeds. This study will provide an exploratory understanding of the age-dependent toxicity of 4'-O-methylpyridoxine.

Ultrasound-assisted adsorption/desorption of jujube peel flavonoids using macroporous resins.

The work explored the process of ultrasound-assisted adsorption/desorption to efficiently purify jujube peel flavonoids (JPFs) using macroporous resins (MRs). The impact of ultrasound power and temperature on the adsorption/desorption features of JPFs on MRs were studied. The maximum adsorption (80.21 ± 2.11 mg/g) /desorption (76.22 ± 1.68 mg/g) capacity of total flavonoids content were obtained. The pseudo-second-order kinetic and Freundlich isotherm models better described the whole process of ultrasound-assisted adsorption. The adsorption process was spontaneous, physical, and dominated by multilinear intraparticle diffusion. Ultrasound mainly enhanced the adsorption capacity by strengthening the formation of hydrogen bonds and increasing the surface roughness of MRs. Besides, the principal individual flavonoid ((+)-Catechin, (-)-Epicatechin, Rutin, Quercetin-3-O-robinobioside) content of JPFs in ultrasound treatment was 2-3 times that of shaking treatment, and biological activities were significantly increased. Overall, as a low-cost green technology, ultrasound can improve the properties of MRs and better purify JPFs.

In vivo toxicity assessment of 4'-O-methylpyridoxine from Ginkgo biloba seeds: Growth, hematology, metabolism, and oxidative parameters.

4'-O-methylpyridoxine (MPN), a recognized antivitamin B6 compound, is a potentially poisonous substance found in Ginkgo biloba seeds and leaves. In this work, the body weights, histopathological changes, plasma vitamin B6 (VB6), biochemical parameters, oxidative stress responses, and amino acids of rats were investigated after intragastric administration of MPN for 15 days. Results showed that intragastric administration of 50 mg/kg BW MPN caused pathological changes in the brain and heart tissues of rats. Administration of 10 mg/kg and 30 mg/kg BW MPN can significantly increase VB6 analogs in the plasma of rats, such as pyridoxal-5'-phosphate, pyridoxal. Results of biochemical parameters indicated that MPN can damage brains and hearts by changing the enzyme activity of these organs. These results suggest that consumption of Ginkgo biloba seeds for the long term, even in a small quantity, may lead to poisoning.

4'-O-methylpyridoxine: Preparation from Ginkgo biloba Seeds and Cytotoxicity in GES-1 Cells.

Ginkgo biloba seeds are wildly used in the food and medicine industry. It has been found that 4'-O-methylpyridoxine (MPN) is responsible for the poisoning caused by G. biloba seeds. The objective of this study was to explore and optimize the extraction method of MPN from G. biloba seeds, and investigate its toxic effect on human gastric epithelial cells (GES-1) and the potential related mechanisms. The results showed that the extraction amount of MPN was 1.933 µg/mg, when extracted at 40 °C for 100 min, with the solid-liquid ratio at 1:10. MPN inhibited the proliferation of GES-1 cells, for which the inhibition rate was 38.27% when the concentration of MPN was 100 µM, and the IC50 value was 127.80 µM; meanwhile, the cell cycle was arrested in G2 phase. High concentration of MPN (100 µM) had significant effects on the nucleus of GES-1 cells, and the proportion of apoptotic cells reached 43.80%. Furthermore, the Western blotting analysis showed that MPN could reduce mitochondrial membrane potential by increasing the expression levels of apoptotic proteins Caspase 8 and Bax in GES-1 cells. In conclusion, MPN may induce apoptosis in GES-1 cells, which leads to toxicity in the human body.

Evaluation of proximate composition, flavonoids, and antioxidant capacity of ginkgo seeds fermented with different rice wine starters.

Ginkgo seeds are distinguished as source of highly promising food and traditional Chinese herbal for thousands of years. It is well known for the significant curative effects on some diseases, such as cough and asthma. The current work aimed to study the proximate composition, phytochemical content, and antioxidant capacity of ginkgo seeds fermented by 17 varieties of rice wine starters. Solid state fermentation was used to improve the nutrition of ginkgo seeds. Correlation analysis showed that there was a significant correlation between the flavonoids, approximate composition, and antioxidant activity in fermented ginkgo seeds. Through principal component analysis (PCA), Yp rice wine starter was found as the most suitable for ginkgo seeds fermentation. After fermentation of Yp rice wine starter, the content of quercetin increased by 188.1%, the content of reducing sugars and peptides increased by 16 and 24 times, respectively, and the scavenging ability of 1,1-diphenyl-2-picrylhydrazyl free radicals increased from 4.69 to 12.43 mg TE/g. The solid-state fermentation of ginkgo seeds could be efficiently applied to food industrial production, and fermentation significantly increased the antioxidant activity and flavonoid content of ginkgo seeds, as well as improved their nutrition. PRACTICAL APPLICATION: Traditionally, rice wine starter was used for brewing wine, only some folk use rice wine starter for food production. In this paper, ginkgo seeds are selected for fermentation, which not only solves the problem of ginkgo seeds surplus, but also provides a reliable technical route for industry. It provides reference for the application of rice wine starter in food in the future.

Influence of illumination on the greening and relative enzyme activity of garlic puree.

Garlic has attracted considerable attention because of its bactericidal and anticancer effects. However, the greening of garlic purees greatly affects the product quality. This study investigated the influence of light colors and power on the greening of garlic, and determined the key substances of garlic puree greening, including γ-glutamyl transpeptidase (γ-GT), thiosulfinate, and alliinase. Results showed that purple light source greatly affects greening power, γ-GT, and thiosulfinate. Illumination using a 3-W power lamp could reduce the production of thiosulfinate and alliinase and inhibit the green transformation reaction. Illumination using a 5-W power lamp greatly affected the thiosulfinate content and greening power, whereas that using a 7-W power lamp greatly influenced the γ-GT activity, porphobilinogen content, and alliinase content. Results showed that the green color of garlic puree is greatly affected by the illumination color and intensity, which provides theoretical support for the anti-greening of light garlic puree. PRACTICAL APPLICATION: Because garlic puree easily turns green during processing, which affects the product quality and economic value, this study uses controllable light source radiation to influence the greening of garlic puree, hoping to delay or even solve this problem and provide a new simple method to prevent garlic puree from turning greening.

Influence of packaging materials on postharvest physiology and texture of garlic cloves during refrigeration storage.

This study aims to investigate the postharvest physiology and texture of garlic cloves packaged in polyethylene terephthalate (PET), polyethylene (PE), aluminized kraft paper (AKP), single kraft paper (SKP), and mesh bag. Germination rate, electrical conductivity, respiration intensity, water content, and texture were determined during 180 d storage at -2 °C. Results showed that the germination of garlic cloves packaged in PET, PE, and AKP was effectively inhibited during storage. PE effectively reduced the degree of damage to the cell membranes of the garlic cloves. PE and SKP significantly inhibited respiratory intensity during storage. Garlic cloves water content did not change significantly in 90 d storage which packaged in PE and SKP. PE exhibited better effect on the texture and freshness of garlic cloves than the other materials. In conclusion, PE is the best packaging material for maintaining the quality attributes and extending the shelf lives of garlic cloves.

Improvement of Biological Activity of Morchella esculenta Protein Hydrolysate by Microwave-Assisted Selenization.

Morchella esculenta protein hydrolysate (MPH) from a valued medicinal and edible fungus M. esculenta (L.) is an excellent material for functional food development. To promote MPH utilization, selenization of MPH was performed by applying a simple and environmentally friendly microwave irradiation procedure. The physicochemical characteristics of selenized MPH (Se-MPH) were investigated by SEM-EDX, FTIR, CD, and amino acid analyzer, and its biological activity were assessed by ABTS, DPPH, H2 O2 scavenging, and reducing power assays, as well as α-glucosidase, α-amylase, and tyrosinase inhibition tests. The results showed that MPH was successfully selenized, Se content in Se-MPH reached 59.0 ± 0.64 mg/g, and amino groups, hydroxyl groups, and sulfur atoms of methionine residues in the MPH molecule may participate in selenization. Furthermore, Se-MPH exhibited significantly enhanced antioxidant, antidiabetic, and tyrosinase inhibitory activities, compared with the native MPH and microwave-irradiated MPH. Thus, the microwave-assisted selenization is a feasible strategy for preparing organic Se and improving the biological activity of MPH. PRACTICAL APPLICATION: In this study, selenized Morchella esculenta protein hydrolysate (Se-MPH) was successfully prepared via conjugation with sodium selenite using the microwave-assisted method. The results showed that Se-MPH, synthesized with the aid of microwave, exhibited favorable selenium content and improved antioxidant, antidiabetic, and tyrosinase inhibitory activities. Therefore, microwave can be employed as an innovative and effective avenue for the production of organic selenium in nutraceutical and functional food industry.

Determination and Comparison of 4'- O-Methylpyridoxine Analogues in Ginkgo biloba Seeds at Different Growth Stages.

The antivitamin B6, 4'- O-methylpyridoxine (MPN); its glucoside, 4'- O-methylpyridoxine-5'-glucoside (MPNG); and vitamin B6 compounds, including pyridoxal (PL), pyridoxamine, pyridoxine, pyridoxal-5'-phosphate (PLP), and pyridoxamine-5'-phosphate, exist in Ginkgo biloba seeds, which are widely used as food and medicine. This work aimed to determine the MPN analogues in G. biloba seeds at different growth stages in terms of cultivars and ages of trees. The highest total MPN contents of 249.30, 295.62, and 267.85 µg/g were obtained in the mature stages of three selected G. biloba samples. The total contents of vitamin B6 compounds decreased significantly in the entire growth period of the three samples. Principal-component analysis revealed that MPN and MPNG were important contributors in the MPN-analogue metabolism of G. biloba seeds. The influence of the cultivar on the content and composition of MPN analogues was greater than that of the age of the G. biloba tree.

Ginkgo biloba extracts-loaded starch nano-spheres: Preparation, characterization, and in vitro release kinetics.

Ginkgo as a promising edible material and herbal medicine has received much attention due to its abundant starch contents and functional ingredient ginkgo biloba extracts (GBEs). Many foreign scholars suggest that GBEs can effectively ameliorate the symptoms of mild memory impairment and Alzheimer's dementia. However, an insurmountable problem with application of the GBEs is its low bioavailability, which restricts its application in vivo. Considering the biocompatibility between GBEs and starch, we have prepared ginkgo and corn starch-based nano-carriers, and thereby loaded GBEs onto starch nano-spheres (SNPs) by nanoprecipitation. Compared with unloaded SNPs (201-250nm), the mean sizes of the monodispersed and spherical GBEs-loaded SNPs were 255-396nm. Moreover, the loading amounts of GBEs onto ginkgo, and corn SNPs were 0.661-1.045, and 0.560mg/mg, respectively. In addition, in artificial gastric and intestinal juices, the GBEs-loaded SNPs exhibited a better sustained release than free GBEs.

Comparison of Phytochemicals and Antioxidant Capacity in Three Bean Varieties Grown in Central Malawi.

The aims of the current work were: (1) to study the influence of variety and geographical production area on the total phenolic content, total anthocyanin content, total flavonoid content, total carotenoid content and antioxidant activity in bean varieties (Dimeta, Napirira and Nanyati) from different growing areas in central Malawi, and (2) to evaluate the possibility of establishing a classification based on the geographical areas of the growing regions. A total of 47 bean samples were collected from Makowe, Mphathi, Chuma-Chitsala and Khulungira Zone. These four locations were segregated based on altitude, latitude and longitude. Principal component and hierarchical cluster analysis were used to distinguish and classify among these samples. Significant differences (P < 0.05) in total phenolic content (2.92-4.97 mg/g), total anthocyanin content (14.52-152.31 µg/g), total flavonoid content (2.01-6.38 mg/g) and oxygen radical absorbance capacity (16.75-24.51 µmol/g) were found among the different sampled villages, showing a significant effect of the producing region on these parameters. The beans in Makowe had lower polyphenols than in other locations. Results of principal component analysis indicate that phytochemicals and antioxidant capacity could serve as parameters to establish a bean classification according to the geographical area of production.