Effect of Tremella fuciformis polysaccharide on the stalling and flavor of tteok during storage

The effect of Tremella fuciformis polysaccharide(TFP)on the retrogradation property and aroma profile changes of tteok during storage was investigated.Results indicated that addition of TFP significantly increased the stability to thermal and mechanical shearing of starch,decreased short-term retrogradation,the hardness and the retrogradation enthalpy(ΔH)of tteok during storage,but had no significant effect on the amylopectin chain length of tteok.The possible mechanism for the retarding staling effect of TFP is related to the interaction between TFP and starch chains that interferes with the alignment of starch chains.Electronic nose and g as chromatography-mass spectrum(GC-MS)analysis results showed that the difference in the concentrations of volatile compounds and fatty acids of tteoks at different storage time gradually increased with the advancement of storage period.The addition of TFP to tteok inhibited the development of unpleasant volatile compounds,probably by delaying the oxidation and decomposition of lipids and preserving the antioxidant phenolic compounds in tteok,thus slowing down the flavor deterioration of tteok and contributing to flavor maintainace.Overall,this study could help food manufacturers to choose a high-effective and natural polysaccharide to control the retrogradation rate and flavor loss of tteok.

Healthy function and high valued utilization of edible fungi

Edible fungi are large fungi with high added value that can be utilized as resources.They are rich in high-quality protein,carbohydrate,various vitamins,mineral elements and other nutrients,and are characterized by high protein,low sugar,low fat and low cholesterol.In addition,edible fungi contain a variety of bioactive substances,such as polysaccharides,dietary fiber,steroids,polyphenols,and most of these compounds have antioxidant,anti-tumor and other physiological functions.This review comprehensively discusses the bioactive components and functional characteristics of edible fungi(such as antioxidant,anti-aging,hypolipidemic activities,etc.).Then the recent developments and prospect in the high-valued utilization of edible fungi are discussed and summarized.The objective of this review is to improve the understanding of health-promoting properties of edible fungi,and provide reference for the industrial production of edible fungi-based health products.

Isolation,purification,structural characteristic and antioxidative property of polysaccharides from A.cepa L.var.agrogatum Don

Allium cepa L.var.agrogatum Don(ALAP)is commonly consumed in China as well as other regions and has various beneficial health effects.A novel acidic polysaccharide(named ALAP-21)was obtained from ALAP by ultrasonic and microwave-assisted extraction and purification using DEAE-52 anion exchange and Sephadex G-100 columns.The monosaccharide composition,structural and antioxidative properties of ALAP-21 were investigated by GC–MS chromatography,FT-IR and NMR spectroscopies and three antioxidative activity tests in vitro.The results showed that ALAP-21 was a heteropolysaccharide composed of glucose,galacturonic acid,mannose,galactose,arabinose,rhamnose,xylose,fructose and glucuronic acid with a relative molar ratio of 26.282:27.546:11.400:4.781:2.467:2.445:3.622:1.106:1.753,owning(1→4)-β-d-Glcp,(1→4)-β-d-GalAp6Me3OA,(1→4)-β-d-Galp6OMe,(1→2)-β-l-Rhap,(1→4)-β-d-Manp glycosidic linkages.(1→4)-β-d-Glcp and(1→4)-β-d-GalAp6Me3OA residues might be the main components of the sugar chain backbone of ALAP-21.Furthermore,ALAP-21 exhibited high potential for DPPH radicals(82.02%),hydroxyl radicals(53.33%)and superoxide anion radicals(50.28%).These results provide a reference for further research and rational development of ALAP polysaccharides.

Dynamic microwave-assisted extraction combined with liquid phase microextraction based on the solidification of a floating drop for the analysis of organochlorine pesticides in grains followed by GC

A convenient,cost-effective and fast method using dynamic microwave-assisted extraction and liquid phase microextraction based on the solidification of a floating drop was proposed to analyze organochlorine pesticides in grains including rice,maize and millet.Twelve samples can be processed simultaneously in the method.During the extraction process,10%acetonitrile-water solutions containing 110μL of n-hexadecane were used to extract organochlorine pesticides.Subsequently,1.0 g sodium chloride was placed in the extract,and then centrifuged and cooled.The n-hexadecane drops containing the analytes were solidifi ed and transferred for determination by gas chromatography-electron capture detector without any further filtration or cleaning process.Limits of detection for organochlorine pesticides were 0.97–1.01μg/kg and the RSDs were in the range of 2.6%–8.5%.The developed technology has succeeded in analyzing six real grains samples and the recoveries of the organochlorine pesticides were 72.2%–94.3%.Compared with the published extraction methods,the developed method was used to analyze organochlorine pesticides in grains,being more environmentally friendly,which is suitable for the daily determination of organochlorine pesticides.

Review on plant-derived bioactive peptides:biological activities,mechanism of action and utilizations in food development

Plant proteins are good alternative to animal sources in bioactive peptide production due to their safety,low-cost,rich resources and easy for large scale production.The bioactivities of the peptides derived from plant proteins including antihypertensive,hypocholesterolemic,immunomodulatory,antioxidant,antimicrobial,anti-diabetic,opiate and hepatoprotective effect are being increasingly recognized with regards to health promoting and disease prevention.In addition to bioactivities,the plant-derived bioactive peptides possess various functional properties including emulsifying and foaming properties,and water and oil retention capacities owning to the hydrophilic/lipophilic property,conformational flexibility and chain length of peptides.Hence,the plant-derived bioactive peptides are promising ingredients for the development of health-care and functional products.This review provides the research progress on the biological activities and functional properties of plant derived peptides.The mechanism of action and structure-activity relationships of the bioactive peptide were also described,when known.Furthermore,recent developments,major challenges and prospect in the application of the plant-derive bioactive peptides in the development of functional products are discussed and summarized.The objective of this review is to improve the understanding of plant-derive bioactive peptides,and provide some constructive inspirations for further research and industrial application in the food and medicine industry.