To investigate the effects of ordinary PE packaging(CK)and physically active packaging(PA)on post-harvest storage quality,respiratory metabolism,and energy metabolism of Lentinula edodes,L.edodes'808'was used as experimental material,and stored at(4±1)℃ and 90％±5％relative humidity for 12 d.The sensory evaluation,weight loss,hardness,total soluble solids,soluble protein,respiration rate,key enzyme activities in respiration and energy metabolism,energy substance,and energy charge of L.edodes were measured every 3 d.The results showed that PA treatment delayed the deterioration of the sensory quality of L.edodes,inhibited the increase of the weight loss rate,retarded the decline of the hardness,total soluble solids,and soluble proteins,reduced the respiratory intensity,and postponed the emergence of L.edodes respiratory peaks.Further research indicated that L.edodes under PA treatment were able to maintain higher levels of cytochrome C oxidase(CCO)and malate dehydrogenase(MDH)enzyme activities while inhibiting the rapid increase in glucose-6-phosphate isomerase(PGI),succinate dehydrogenase(SDH)and pyruvate dehydrogenase(PDH)enzyme activities.Meanwhile,PA treatment also suppressed the degradation of ATP and ADP in L.edodes,and maintained a high level of energy charge.The correlation analysis revealed that the sensory quality of L.edodes was a highly significantly positive correlation with hardness,total soluble solids,MDH,ATP,and energy charge(P＜0.01),significantly positive correlation with soluble proteins and ADP(P＜0.05),and highly significantly negative correlation with weight loss,and AMP(P＜0.01),indicating that storage quality of L.edodes during storage in PA group was strongly correlated with energy levels.Therefore,physical active packaging can effectively inhibit the post-harvest respiration and energy metabolism of L.edodes,maintain storage quality,and reduce economic losses.

In order to investigate the effect of ABP(Agaricus bisporus powder)on the physicochemical properties of yogurt,ABP with different mass fractions(0.0％,1.5％,3.0％,4.5％,6.0％and 7.5％)was added to yogurt while using yogurt as the raw material,and the rheological and textural properties of yogurt were investigated at different ABP additions.The findings demonstrated that with the addition of ABP at 1.5％,the dynamic viscoelasticity,apparent viscosity,consistency,hardness,and cohesiveness of yogurt were decreased compared with the control group,while the dynamic viscoelasticity,apparent viscosity,consistency,hardness and cohesiveness of yogurt increased with a higher addition of ABP at over 1.5％.Moreover,the scanning electron microscopy results suggested that yogurt with ABP addition at 0.0％and 1.5％showed casein fibrillar network structure with more voids,and with the increase of ABP addition,the voids in the fibrous network were gradually filled by ABP particles,thus forming a dense and continuous spatial structure,which ultimately enhanced the hardness,consistency,and stability of the yogurt.According to the comprehensive analysis,the addition of ABP at 1.5％～3.0％will result in better rheological and textural properties of yogurt.In conclusion,these findings could provide theoretical and data support for the research and development of Agaricus bisporus-flavored dairy products.

To investigate the effects of three circulation methods including normal temperature,cold chain,and broken cold chain on the flavor substances of fresh Lentinula edodes before and after storage and transportation,the changing trends of volatile flavor compounds and taste components of L.edodes during simulated transportation under the three temperature conditions were analyzed using an electronic nose,gas chromatography-ion mobility spectrometry(GC-IMS),an electronic tongue,high performance liquid chromatography(HPLC),and an automatic amino acid analyzer.The results showed that electronic nose was able to quickly distinguish between the aroma characteristics of L.edodes under different simulated temperature conditions.In total,55 volatile compounds were detected by GC-IMS,including 16 alcohols,10 aldehydes,8 terpenes,6 ketones,4 esters,and 11 other compounds.The electronic tongue revealed differences in the sourness,bitterness,astringency,umami,richness,and saltiness among early storage and transportation(control),simulated normal temperature logistics(NTL),simulated cold chain logistics(CCL),and simulated broken chain logistics(BCL),with the CCL group being characterized by moderate sourness and prominent umami.In the NTL,CCL,and BCL groups,the total amounts of free umami amino acids were 90.82,81.83,and 84.31 mg/g,respectively,and the 5'-nucleotide contents were 122.99,107.42,and 118.27 μg/g,respectively.Among them,the volatile flavor compounds and taste components in the CCL group were most similar to those in the control group,indicating that consistent low-temperature conditions are helpful for preserving the flavor quality of L.edodes during storage and transportation.In contrast,the BCL group,which experienced temperature fluctuations during both storage and transportation,exhibited slightly lower flavor quality than did the CCL group due to the negative impact on the flavor compounds before entering the shelf life.In conclusion,in the post-harvest circulation process of L.edodes,cold-chain transportation is needed to minimize quality deterioration caused by temperature fluctuations during storage and transportation.The results provide valuable insights for improving the cold chain distribution system for L.edodes.

In order to investigate the effects of different doses of 60Co-y-ray irradiation on rice,this experiment employed a texture analyzer,a rapid viscosity analyzer,a differential scanning calorimeter,a rheometer,an X-ray diffractometer,and a Fourier transform infrared spectrometer to characterize the eating quality of rice and the physicochemical properties and structure of rice starch.The results indicated that as irradiation dose increased,the water absorption and volumetric expansion of rice during cooking,and the pH,dissolved solid content and iodine blue value of rice broth fell significantly(P＜0.05).High doses of irradiation resulted in a noticeable increase in the total color difference(△E)of rice compared with that before irradiation,and a △E of 12.53 was obtained at 10 kGy,indicating a significant color change.Also,the irradiation notably affected the hardness of cooked rice.The peak viscosity,setback value,and gelatinization enthalpy of rice starch decreased significantly(P＜0.05)with the increase in irradiation dose;the irradiation also reduced the rigidity,elasticity,relative crystallinity and orderliness of rice starch,with the crystallinity being decreased from 23.68％to 15.69％.The measurement results of cooking indicators,rice soup properties,△E,and texture characteristics indicate that higher irradiation doses reduced the edible quality of rice.Moreover,the contents of slowly digestible starch and resistant starch in irradiated rice starch increased,with the latter being increased to 20.22％after irradiation treatment at 4 kGy.Compared with the unirradiated control,the irradiation reduced the hydrolysis rate of starch.Overall,y-ray irradiation altered the crystalline structure of starch,thereby enhancing its pasting and rheological properties and inhibiting its digestibility,but rice is not suitable for high doses of irradiation treatment.This study provides theoretical guidance for the production of irradiated rice and its products,as well as for the modification of starch.

To better determine how gamma irradiation (GI) improves abiotic stress resistance, a transcriptome analysis of postharvest L. edodes in response to 1.0 kGy GI was conducted, and further the underlying mechanism of GI in delaying quality deterioration over 20 d of cold storage was explored. The results suggested that GI was involved in multiple metabolic processes in irradiated postharvest L. edodes. In comparison with the control group, the GI group contained 430 differentially expressed genes, including 151 upregulated genes and 279 downregulated genes, which unveiled characteristic expression profiles and pathways. The genes involved in the pentose phosphate pathway were mainly upregulated and the expression level of the gene encoding deoxy-D-gluconate 3-dehydrogenase was 9.151-fold higher. In contrast, the genes related to other energy metabolism pathways were downregulated. Concurrently, GI inhibited the expression of genes associated with delta 9-fatty acid desaturase, ribosomes, and HSP20; thus, GI helped postpone the degradation of lipid components, suppress transcriptional metabolism and regulate the stress response. Additionally, the metabolic behavior of DNA repair induced by GI intensified by noticeable upregulation. These regulatory effects could play a potential and nonnegligible role in delaying the deterioration of L. edodes quality. The results provide new information on the regulatory mechanism of postharvest L. edodes when subjected to 1.0 kGy GI during cold storage.

Stropharia rugosoannulata, a high-value mushroom, exhibits high nutritional value and flavor characteristics; however, the mushroom is susceptible to spoilage, water loss and texture deterioration, which renders its safety and edibility a challenge. To improve the shelf life of fresh mushrooms during storage, a novel nanocomposite packaging (NP) was applied for the first time to maintain the freshness of S. rugosoannulata. The results showed that compared to other groups, NP effectively delayed the deterioration of sensory quality, postponed the decrease in firmness, and inhibited the degradation of soluble protein (caps 54.58 mg g(-1) and stipes 31.45 mg g(-1)) and crude polysaccharide (caps 5.06 mg g(-1) and stipes 3.53 mg g(-1)). Moreover, NP significantly reduced weight loss (0.41%) and water content loss (caps 90.93% and stipes 89.80%), as confirmed by low-field nuclear magnetic resonance and magnetic resonance imaging; thus, water loss was inhibited. Additionally, the results of scanning electron microscopy and transmission electron microscopy indicated that NP helped preserve intact cell structure and retard organelle disintegration, helping prevent water from escaping to some extent. The overall research indicated that the application and performance of the novel NP, which is convenience, suitable for scale application and improves postharvest quality, is a promising approach for extending the shelf life of fresh S. rugosoannulata.