Objective To establish a solution for fungal culturomics in food by comparing the performance of 3 fungal culture media and optimising fungal culturomics techniques. Methods The 24 food samples and 2 proficiency test samples were tested using commonly used fungal culture media for food testing, including potato dextrose agar (PDA), rose Bengal agar, and a novel Pan Fungi medium (PF). The cultured fungi were isolated and identified using matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Results Yeast phase fungi could grow well on all 3 kinds of media, and the colony growth rate, colony morphology size and colony numbers had no significant difference. Filamentous fungi were able to grow well on the 3 kinds of medias, but growth rate and colony morphology were significantly different. There were 12 kinds of fungal species identified in the 24 samples, including 2 kinds of yeast phase fungi and 10 kinds of filamentous fungi. Conclusion With excellent accuracy and stability and self-limited growth of cultured colonies, PF fungal medium is favourable for isolation and identification of single colonies, and can be used as a supplement to the commonly used fungal medium for fungal culturomics studies in food.

Starch as an important component of edible films, has many advantages such as safety, degradability, low cost, and wide availability. Chitosan is widely used in food packaging films due to its good biodegradability, antioxidant, antibacterial, and good film-forming properties. The application of chitosan in starch based edible films and the development of packaging materials with good biodegradability and safety is a research hotspot in the food packaging industry. This paper reviewed the structure, film-forming properties, and biological activity of chitosan, and elucidated the film-forming mechanism of chitosan starch based edible films and the film-forming properties of chitosan in different types of starch matrices, discussed the application of chitosan-starch composite edible film in meat, fruits, vegetables, and other foods. With the deepening of research, chitosan starch based edible packaging film has broad development prospects in the future. This paper provides a basis and direction for the application of chitosan in starch based edible film, and provides a good theoretical basis for its application in new food packaging.

Objective To achieve accurate and non-destructive detection of Zea mays L. seed maturity by applying hyperspectral imaging technology combined with multimodal fusion methods. Methods Hyperspectral images of high and low maturity Zea mays L. seeds were acquired. The cascade algorithm of bootstrapping soft shrinkage and successive projections algorithm (BOSS-SPA) was used for feature wavelength extraction, while the gray-level co-occurrence matrix method (GLCM) was used for image texture feature extraction. Five feature parameters—energy, entropy, correlation, homogeneity and contrast were selected to integrate the spectra with the image data in a feature level fusion. Results The partial least squares-discriminant analysis (PLS-DA) and least squares support vector machine (LS-SVM) were used to establish a Zea mays L. seed maturity classification model. The use of Savitzky-Golay convolution smoothing-standard normal variable transformation (SG-SNV) was identified as the best spectral preprocessing method, and the 11 wavelengths extracted using the BOSS-SPA method showed good modelling performance, and the overall recognition accuracies of the model test set based on the fused data of the spectral images all reached over 95%. Conclusion Hyperspectral technology combined with multimodal feature fusion method is expected to provide a practical reference method for non-destructive detection of Zea mays L. seed maturity.

Objective To study the effect of n-3 polyunsaturated phosphatidylserine on the anti-apoptotic ability of rat hippocampal neuron cells (RHNC). Methods An apoptosis model using RHNC as the target and phorbol acetate (PMA) as the inducer was established. Using docosahexaenoic acid (DHA)/eicosapentaenoic acid (EPA) phosphatidylserine (DHA/EPA-PS) as a protective agent, the morphology of cells at different stages of apoptosis was observed under a laser confocal microscope after staining with acridine orange. The effect of n-3 polyunsaturated phosphatidylserine, represented by DHA/EPA-PS, on the anti-apoptotic ability of RHNC was studied at the cellular level through the Annexin V-FITC/PI double staining experiment. Results An RHNC apoptosis model with a PMA concentration of 10.0 mg/L and an action time of 24 hours was established. The 15.0 mg/L DHA/EPA-PS showed the best cell pre protection effect, with an apoptosis rate of 11.46%±4.11%. Early and mid-stage apoptotic cells were fewer and did not produce late stage apoptotic cells. Cells pre protected with 15 mg/L DHA/EPA-PS exhibited intact morphology and nuclear membrane, and their protrusions were not affected by PMA. Conclusion n-3 polyunsaturated phosphatidylserine, represented by DHA/EPA-PS, has certain anti-apoptotic ability against RHNC. The study provides good data support for future research on the biological activity of phosphatidylserine.

Objective To study the difference of meat quality between adult and young Xueduo yaks. Methods Healthy adult and young castrated Xueduo yaks were selected to analyze the composition and content of conventional nutrients, edible meat quality, amino acids, fatty acids, vitamins and minerals in longissimus dorsi muscle. Results The moisture content of adult Xueduo yak meat was 72.89%, which was lower than that of young Xueduo yak meat. The crude protein, crude fat and crude ash contents of adult Xueduo yak meat were 4.99%, 86.67% and 38.54% higher than those of young Xueduo yak meat, respectively. Therefore, adult Xueduo yak meat had higher nutritional value. The edible meat quality of young Xueduo yak meat was excellent, and the color, taste and tenderness were better than those of adult Xueduo yak meat. Both adult and young Xueduo yak meat were high-quality protein sources. The contents of essential amino acids and total amino acids in young Xueduo yak meat were 5.95% and 14.00%, which were significantly higher than those in adult Xueduo yak meat, but adult Xueduo yak meat tastes more delicious. The fatty acid composition of young Xueduo yak meat was slightly better than that of adult Xueduo yak meat. In terms of vitamin and mineral composition and content, vitamin A in young Xueduo yak meat was significantly higher than that in adult Xueduo yak meat. The iodine content of adult Xueduo yak meat was significantly higher than that of young Xueduo yak meat. Conclusion The meat quality of young Xueduo yak is better than that of adult Xueduo yak. The growth cycle of young Xueduo yak is short, which can create higher economic value under limited forage resources. At the same time, it can improve the market competitiveness of yak meat and provide scientific and effective guidance for yak breeding in pastoral areas.

Objective To optimization of enzymatic hydrolysis of yak butter based on response surface design. Methods Employed lipase to enzymatically treat yak butter. The 3 factors of enzyme addition, enzymatic hydrolysis time and enzymatic hydrolysis temperature were determined as independent variables by single factor test. The sensory score of ghee and ghee milk tea was taken as the response index, and the enzymolysis process of yak milk ghee was optimized by response surface methodology. Results When the addition amount of lipase was 0.48%, the enzymatic hydrolysis time was 3.75 h, and the enzymatic hydrolysis temperature was 46 ℃, the optimal enzymatic hydrolysis effect could be obtained. Under these conditions, the enzymatic hydrolysis yak milk ghee had bright color, pure frankincense flavor, and the odor of ghee was significantly improved. The ghee milk tea prepared with enzymatic hydrolysis yak milk ghee had moderate smell, unique taste, and better sensory evaluation. Conclusion The method of enzymatic hydrolysis of yak milk ghee by lipase can effectively improve the taste and odor of yak milk ghee, optimize the smell of ghee, and improve the sensory quality of its additional products, which provides new ideas and technical support for the further development of Tibetan characteristic products.

In recent years, with the increasing emphasis on health and the increasing awareness of environmental protection, people have gradually explored and put forward more stringent and comprehensive requirements in the analysis of the total amount and form of elements in food and medicine. Although traditional extraction methods can meet the needs of analysis to a certain extent, they often accompanied by various problems. Therefore, exploring more green, efficient and environmentally friendly element extraction technology has become an important thing. As a biocatalyst, enzyme has attracted increasing attention in the field of element extraction because of its unique advantages, such as high specificity, mild reaction conditions and environmental friendliness. Enzymatic extraction is a method that using the biochemical action of enzymes to destroy the structure of the sample and breaking the macromolecules into amino acids, so as to extract metal elements. This paper reviewed the application of enzymes in the extraction of elements in cereal foods, vegetables, traditional Chinese medicine, seafood and feed, and discussed which enzymes are suitable for different matrices, the advantages and disadvantages of enzymatic extraction methods, so as to better understand the compatibility of enzymes with different samples. It provides a reference for the future use of enzymatic extraction in the total amount and form of elements in different substances.

Objective To evaluate and determine the key volatile aroma components of Jinzhuguo Pyrus. Methods Head space-solid phase microextractio (HS-SPME) and gas chromatography-mass spectrometry (GC-MS) were used to separate and identify the volatile aroma components in the peel, pulp and juice of Jinzhuguo Pyrus. The odor activity value (OAV) was determined by combining the odor threshold to evaluate the contribution of various aroma components. Results The results indicated that the common key flavor compounds in the peel, pulp and juice of Jinzhuguo Pyrus were ethyl n-hexanoate, ethyl butyrate, ethyl octanoate and nonal. The unique key flavor compounds in the peel samples were hexyl butyrate (OAV 2.34), ethyl cromarate (OAV 1.93) and dammasone (OAV 675) in the peel, pulp and juice samples, respectively. The relative content of volatile aroma components in peel, pulp and juice was 88.19%, 76.46% and 39.94%, respectively. Conclusion The OAV of Jinzhuguo Pyrus juice is higher, while it is lower in pulp and peel, making them more suitable for making processed products.

Objective To investigate the key factors that may influence plasmin activity during the production of ultra high temperature (UHT) milk. Methods An enzyme-linked immunosorbent assay (ELISA) was employed to assess and analyze the effects of various factors on plasmin activity throughout the UHT milk production process. The specific factors examined included the degree of mastitis in cows, somatic cell count in milk, vaccination status, changes in feeding conditions, centrifugation processes, pasteurization preheating conditions, microfiltration techniques, and UHT preheating conditions. Results At the raw milk stage, a significant positive correlation was observed between plasmin activity levels in bovine milk and both the severity of bovine mastitis and somatic cell counts. However, no significant correlation was found regarding vaccination status or changes in feed type. During UHT milk production, centrifugal sterilization resulted in a slight increase in plasmin activity; pasteurization preheating at 55 ℃ proved most effective at inhibiting this increase. Microfiltration reduced plasmin activity by approximately 10%. Additionally, varying UHT preheating conditions led to an overall increase in enzyme activity; however, under treatment at 90 ℃ for 5 seconds, a condition yielding only a minimal increase of 1.52%, the rise remained relatively low. Conclusion For pasture, it is essential to focus on managing cows with mastitis and monitoring those milk with abnormal somatic cell counts. At the processing stage, implementing appropriate preheating conditions for pasteurization and UHT can effectively inhibit increases in plasmin activity within milk. Furthermore, incorporating microfiltration can serve as an additional strategy to reduce such enzymatic activities. This study provides a scientific foundation for further research aimed at controlling elevations of plasmin activity in UHT milk.

Objective To investigate the effects of different processes on nutritional compositions and minerals in the processing of tender Laminaria japonica. Methods In this paper, the effects of blanching and salting processes on the main nutritional compositions and minerals of tender Laminaria japonica during processing were studied. Results The content of water, crude protein, dietary fiber, crude fat, alginate, mannitol, iodine, amino acids, manganese, phosphorus, iron, and potassium in fresh tender Laminaria japonica were the highest, followed by blanched tender Laminaria japonica, and the lowest was salted tender Laminaria japonica, which might be due to the high temperature of blanching and the dehydration process of salting, resulting in varying degrees of loss of nutrients in tender Laminaria japonica. Amino acid composition analysis showed that fresh tender Laminaria japonica was more in line with the ideal protein pattern recommended by Food and Agricultural Organization of the United Nations/World Health Organization (FAO/WHO). Heavy metal content analysis showed that the content of heavy metal elements in tender Laminaria japonica met the food safety standards at home and abroad. The results of principal component analysis showed that the comprehensive scores of fresh tender Laminaria japonica was the highest and the quality was the best. After blanching and salting, the comprehensive nutritional quality of fresh tender Laminaria japonica decreased. Conclusion During the processing of tender Laminaria japonica, nutritional compositions and minerals are lost to varying degrees after blanching and salting. This study can provide a scientific basis for the high-value development, utilization, and sustainable development of tender Laminaria japonica in the future.