Effect of wall-disruption on nutrient composition and in vitro digestion of camellia and lotus bee pollens

The nutrient digestion,absorption and biological activity of bee pollen may be limited due to the complex pollen wall.Here,the effect of superfine grinding technology on the release of nutrients from bee pollen were investigated,and their antioxidant activities and in vitro digestion were explored in this study.Results showed that the content of nutrients in bee pollen increased after wall disruption.Among them,fat content increased by 22.55%-8.31%,protein content increased by 0.54%-4.91%,starch content increased by 36.31%-48.64%,soluble sugar content increased by 20.57%-29.67%,total phenolic acid content increased by 11.73%-86.98%and total flavonoids content increased by 14.29%-24.79%.At the same time,the antioxidant activity increased by 14.84%-46.00%.Furthermore,the active components such as phenolic compounds in the wall-disruption bee pollen were more readily to be released during the in vitro digestion,and easier to be absorbed because of their higher bioaccessibility.Antioxidant activities during in vitro digestion were also improved in walldisruption bee pollen.These findings provide evidence that bee pollen wall disruption was suggested,thus,it is more conducive to exerting the value of bee pollen in functional foods.

Bound lipase:an important form of lipase in rice bran (Oryza sativa)

Rice bran residue possessed a steady lipase activity((26.68 ± 3.69)%)after its endogenous lipase was extracted continuously by phosphate buffer solution(PBS)for 24 h. T herefore, the aim of this research was to explore whether there exist any bound lipases in rice bran(Oryza sativa). Three physical treatments(grinding, homogenizing and ultrasound crush)and 6 enzymatic treatments(cellulase, hemicellulase, pectinase, complex cellulase, glucoamylase and α-amylase)were applied to rice bran in order to investigate this bound lipase. The relative catalytic activities of extraction supernatant and residue for pectinase group were(437.63 ± 22.54)% and(159.26 ± 2.12)%, respectively, which were significantly higher(P < 0.05)than other groups. This phenomenon demonstrated that lipase was the most likely to combine with pectin. Molecular simulation proved that pectin could combine with two rice bran lipases(lipase 315 and lipase 308)and cover the catalytic centers so as to prevent the lipases from encountering the substrate and inhibiting their catalytic activities. During combination, pectin could make the lipases more compact and reduce the solvent accessible surface area of lipases, which would make the lipases inactive to molecular interaction. In summary, part of rice bran lipase was proved to exist in bound form and combined with the pectin.

Isolation of a novel characterized Issatchenkia terricola from red raspberry fruits on the degradation of citric acid and enrichment of flavonoid and volatile profiles in fermented red raspberry juice

High content of citric acid in red raspberry juice leads to poor sensory experience. This study developed a feasible method to degrade citric acid in red raspberry juice using a novel characterized Issatchenkia terricola WJL-G4 isolated from red raspberry fruits. I. terricola WJL-G4 exhibited a potent capability of reducing the citric acid contents from(22.8 ± 0.08) g/L to(6.2 ± 0.02) g/L within 36 h fermentation, then completely depleted after 48 h. Furthermore, the contents of phenolic compound, including neochlorogenic acid, p-coumaric acid, raspberry ketone, and rutin significantly increased after 36 h fermentation. Fermentation increased total flavonoid contents in red raspberry juice, compared to that in control group. Volatile profiles exhibited to be enriched after fermentation, which contributed to the improvement of the juice taste. Our findings showed that I. terricola WJL-G4 can be applied in deacidification, enrichment of flavonoid compounds and volatile profiles in fermented red raspberry juice..

A new household ultrasonic cleaning method for pyrethroids in cabbage

Pyrethroid is widely used in developing countries and is a potential threat to human health.So putting forward an effective pyrethroid cleaning method is of vital importance.Clearance of fenpropathrin,cypermethrin and deltamethrin in cabbage by using ultrasonic treatment accompanied with different baking soda concentrations were investigated in this study.The results of response surface methodology showed that the maximum clearance rate was 70.61% for fenpropathrin under the optimal power,treated time,treated temperature and baking soda concentration,which were 260.02 W,10 min,20.15◦C and 0.014 g/mL,respectively.Similarly,the maximum removal efficiency was 73.72% for cypermethrin under 240 W,13.84 min,19.53℃ and 0.014 g/mL,and 92.15%for deltamethrin under 238.99 W,12.42 min,25℃ and 0.013 g/mL.The clearance rate of pyrethroid by this method was significant higher(P<0.05)than traditional cleaning methods(bathing and running water washing).The contents of the compositions such as vitamin C,total soluble sugar,protein and dietary fiber,texture and sensory evaluation of cabbage were not found obvious changes after the ultrasonic treatment combined with baking soda(P>0.05).Results showed that ultrasonic treatment combined with baking soda was an effective way to eliminate the fenpropathrin,cypermethrin and deltamethrin in cabbage without influencing cabbage quality.

Application of high-speed counter-current chromatography coupled with high performance liquid chromatography for the separation and purification of Quercetin-3-O-sambubioside from the leaves of Nelumbo nucifera

Quercetin-3-O-sambubioside[Quercetin-3-O-β-D-xylopyranosyl(1→2)-β-D-glucopyranoside]was separated and purified by semi-preparative high-speed counter-current chromatography(HSCCC)with a twophase-solvent system composed of ethyl acetate-nbutanol-water(4∶1∶5,v/v)from the leaves of Nelumbo nucifera(Lotus).A total of 5.0 mg of the targeted compound with a purity of 98.6%as determined by high performance liquid chromatography(HPLC)was obtained from 100 mg of the crude extract cleaned up by AB-8 macroporous resin in a one-step separation.Quercetin-3-O-sambubioside was a novel flavonoid glycoside from the leaves of Nelumbo nucifera,and its chemical structure was identified by means of ESI-MS,1D NMR and 2D NMR.

Protein security and food security in China

Food security,the need to meet nutritional requirements,and four main problems for food protein security in China are analyzed.From the perspective of residents’nutritional requirements and balanced dietary patterns,the conclusion is that food security in China is in essence dependent on protein production and security of supply and that fat and carbohydrates supply in China can reach self-sufficiency.Considering the situation of food protein production and consumption in China,policy suggestions are made,which could ensure a balanced supply and demand for food protein and food security in China.

Natural bioactive substances for the control of food-borne viruses and contaminants in food

Food-borne viruses and contaminants,as an important global food safety problem,are caused by chemical,microbiological,zoonotic,and other risk factors that represent a health hazard.Natural bioactive substances,originating from plants,animals,or microorganisms,might offer the possibility of preventing and controlling foodborne diseases.In this contribution,the common bioactive substances such as polyphenols,essential oils,proteins,and polysaccharides which are effective in the prevention and treatment of food-borne viruses and contaminants are discussed.Meanwhile,the preventive effects of natural bioactive substances and the possible mechanisms involved in food protection are discussed and detailed.The application and potential effects of natural bioactive substances in the adjuvant treatment for food-borne diseases is also described.