Objective To establish a rapid method for the determination of 5 kinds of nucleotides (cytidine-5’-monophosphate, adenosine-5’-monophosphate, uridine-5’-monophosphate, guanosine-5’-monophosphate and inosine-5’-monophosphate) in infant formulas and dairy products is developed based on mixed-mode hydrophilic interaction/ion exchange chromatography-ultraviolet detection (HILIC/IEX-UV). Methods A zwitterionic hydrophilic interaction chromatography column (Alphasil S-Xion) was used, with mobile phase consisting of 5 mmol/L KH₂PO₄ (pH adjusted to 3.0 with H₃PO₄)-acetonitrile (70:30, V:V) to detect nucleotides in infant foods and dairy products. Results The five nucleotides were baseline separated within 10 min, demonstrating efficient chromatographic performance. They exhibited good linearity within the range of 2-50 μg/mL, with limits of detection (LODs) between 0.19 and 0.66 mg/kg, and limits of quantification (LOQs) ranging from 0.62 to 2.19 mg/kg. At spiked levels of 50, 100 and 200 mg/kg, the intraday recoveries ranged from 96.6% to 108.9%, with relative standard deviations (RSDs) of 1.5%-6.3%, while the interday recoveries were between 101.0% and 108.0%, with RSDs of 2.4%-7.3%. Conclusions Compared with the traditional reversed-phase ion-pair chromatography, this method has significant advantages: Effectively reducing the matrix interference, shortening the analysis time, improving the detection efficiency, and especially improving the quantitative accuracy of cytidine-5’-monophosphate. The proposed method is rapid, accurate, and anti-interference, which provides technical support for the efficient analysis of nucleotides in infant formulas and dairy products.

Extruded rice noodles are made from rice as raw material, ground and blended to a certain moisture content, extruded and matured, and dried. The traditional production process of rice noodles is laborious and time-consuming, which lead to uneven product quality during the multi-step rice noodle production process. By comparison, extrusion technology is a food processing technique that integrates mixing, heating, sterilization, and shaping. Applying extrusion technology to rice noodle processing has the advantages of less loss of nutrients, fewer opportunities for microbial contamination, shorter production time, higher production efficiency, and easier operation. Therefore, in the production of rice noodle processing industry in China, automated mechanical processing is gradually replacing traditional manual workshops. The quality of extruded rice noodles is mainly affected by the raw materials, processing technology, and extrusion parameters during the production process of extruded rice noodles. Therefore, this paper elaborated on the processing technology and forming mechanism of extruded rice noodles, summarized the influence of raw materials and extrusion parameters on the quality of extruded rice noodles, in order to provide theoretical basis for the control of the processing technology and key points of extruded rice noodles.

Bamboo shoot shells, which constitute approximately 60% of the total mass of the bamboo shoot, represent a significant byproduct of bamboo shoot processing. Currently, issues such as low utilization rates and resource wastage persist. To enhance the comprehensive utilization of bamboo shoot shells, this study summarized the key nutrients (including cellulose, hemicellulose, lignin) and active compounds (including flavonoids, polyphenols, sterols, and polysaccharides) found in bamboo shoot shells, based on a review of both domestic and international literature. Additionally, it outlined the extraction and processing technologies for these active substances, highlighting their respective advantages and disadvantages. It also discussed the development and utilization prospects of bamboo shoot shells in various fields such as food, textiles, edible fungus cultivation, animal feed, and liquid fuel. Furthermore, it provided insights into future development directions of the processing and utilization of bamboo shoot shells, aiming to serve as a reference for enhancing the added value and effective utilization of bamboo shoot shells.

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.

Objective To study the characteristics of volatile flavor substances in beef jerky products processed by different processing methods. Methods Beef was processed by different processing methods (15 kinds of curing, bacterial curing, air-drying, etc.), and analyzed by headspace solid-phase microextraction combined with comprehensive two-dimensional gas chromatography-time of flight mass spectrometry. Results The differential metabolites in 15 kinds of samples were detected. Among them, during the pickling process of Staphylococcus xylosus, Lactobacillus plantarum and Pediococcus pentosaceus, the significant differential metabolites included 12 kinds of sugars, acids and esters. The cured beef processed by air-drying method and the cured beef with bacteria produced 8 kinds of extremely significant different metabolites such as maltose, decanoic acid and orotic acid after air-drying. More than 11 kinds of differential metabolites including naphthalene, 3-hydroxy-DL-norvaline, L-menthone, n-decanoic acid, D-pinobiose and myristic acid were detected in the cured beef processed by normal baking than in the cured beef processed by vacuum baking. The metabolic pathways involved in vacuum baking were citric acid cycle, alanine, aspartic acid and glutamic acid metabolism, and the metabolic pathways involved in baking were amino sugar and nucleotide sugar metabolism. Conclusion In this study, the changes of volatile flavor substances in beef jerky products with different processing methods are analyzed, which provide methodological guidance for improving the quality and taste of air-drying beef.

Objective To analyze the nutritional components of traditional sour whey and its products and explore its comprehensive utilization value. Methods The traditional sour whey was separated step by step into a variety of homogeneous and stable whey products by composite membrane separation technology. The content of protein, fat, peptide, mineral and lactose was used as evaluation index to analyze the nutritional characteristics and availability direction of these products. Results Four kinds of whey products: Thin cream RQ-1 for milk standardization (fat content 47.4 g/100 g); microfiltration membrane interception liquid RQ-3 was a high-protein and polypeptide drink (protein content 3.52 g/100 g; peptide content 0.92 g/100 g); ultrafiltration membrane interception liquid RQ-5 was a pure peptide type drink (peptide content 0.87 g/100 g); the reverse osmosis membrane interception liquid RQ-9 could be used for the development of mineral drinks (ash content 0.88 g/100 g, 5 major elements detected) and the recycling of lactose (lactose content 3.92 g/100 g). Conclusion “Turning waste into treasure” of traditional sour whey is directly related to the increase of herdsmen's income. The membrane separation method provides a new solution for its comprehensive utilization.

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.

Objective To optimize the production process of casein peptone with yak milk casein as raw material. Methods The combination of alkaline protease and trypsin was used to hydrolyze yak milk casein. On the basis of single factor experiment, according to the principle of Box-Behnken central combination test design, the response surface analysis method of four factors and three levels was adopted, and the degree of hydrolysis was used as the response value. The response surface and contour line were used to obtain the optimal process conditions for the hydrolysis of yak milk casein by the combined enzyme, and then the yak milk casein peptone product was obtained by acid precipitation, neutralization and finally spray drying. Results The results of single factor showed that the degree of hydrolysis of casein increased with the increase of enzyme concentration. When the amount of enzyme added was higher than 2.5%, the degree of hydrolysis increased slowly. With the increase of temperature and pH, the degree of hydrolysis increased first and then decreased. The degree of hydrolysis of yak milk casein reached the maximum when the substrate concentration was 5%, and the substrate concentration would hinder the effect of the enzyme on the cutting site, resulting in a decrease in protein conversion. The results of response surface showed that the degree of hydrolysis was the best when the amount of combined enzyme was 2.6% (alkaline protease:trypsin=4:1), the hydrolysis time was 160 min, the hydrolysis pH was 7.0, the substrate concentration was 5%, and the hydrolysis temperature was 55 °C, which was 23.63%. Conclusion This study optimize the production process of peptone from yak milk casein, and provided support for the further development and utilization of yak milk casein.

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.