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China is the world’s largest walnut producer, with an annual output of 4.795 9 million tons. Walnut kernels have high nutritional value, containing 65%−69% of oil and 15%−20% of protein. Walnut meal, an abundant byproduct of walnut oil production, is mainly used in animal feed and fertilizers with low processing efficiency, whose potential for high-value utilization is far from being excavated. Studies have found that walnut meal contains a large amount of protein (42%−54%), its amino acid composition is rich, and the proportion of amino acids in walnut meal is suitable for human absorption. Walnut meal is a source of high-quality plant protein with a true protein digestibility score of 86.22%, and a biological valence of 98.77%. Therefore, high-efficiency utilization of walnut meal proteins is an important pathway for the high-value utilization of walnut meal. In this article, the composition, structure, and nutritional value of walnut proteins are reviewed. The extraction methods and functional characteristics of walnut proteins are summarized. The effect of modification on their functionalities and digestibility is also summarized. Finally, the application potential of walnut protein in foods is discussed.

In this study, the effect of component migration and interaction with concomitant saponins on the composition and functional properties of the seed storage proteins from Camellia oleifera Abel., a typical woody oil crop in China, was investigated using proteomics and molecular docking. The results showed that the optimal parameters for alkaline extraction were solid/liquid ratio 1:10 (g/mL) and pH 8.0, which resulted in an extraction rate of 75.8%, and a saponin-to-protein ratio of 2.60. The 11S globulins were precipitated at pH 4.5 with a saponin-to-protein ratio of 0.36. Albumin accounted for 69% of the total storage proteins, and coexisted with saponin during the extraction process, thus resulting in a high saponin-to-protein ratio of 3.73. The foaming properties of albumin and globulin from C. oleifera Abel. seeds were larger than 200%, and the emulsifying activity index was 16.7 m2/g. The interaction between saponins and proteins significantly improved the emulsion stability. This study provides theoretical support for the high-value utilization of proteins from C. oleifera Abel. and the development of functional food ingredients.

The structural heterogeneity and complexity of plant cell wall polysaccharides limit the release of phytonutrients in food processing, ultimately affecting the sensory quality, nutritional value, and shelf stability of products. Efficient enzymatic hydrolysis using plant cell wall polysaccharide-degrading enzymes (PCWPE) is a key step in overcoming the plant cell wall, a chemically complex structure composed mostly of polysaccharides, in food processing. PCWPE include cellulase, hemi-cellulase and pectinase, which specifically and efficiently hydrolyze glycosidic bonds in plant cell wall polysaccharides, significantly improving the sensory flavor and nutritional value of products, enhancing the stability of multiphase systems, and increasing the product yield. In recent years, PCWPE have been widely used in beverage processing, phytonutrient extraction, functional sugar preparation, and the processing of emerging sustainable plant-based food and thereby have become a research hotspot in the field of green food processing. This article summarizes the latest research on the mechanism of action of PCWPE, efficient enzymatic hydrolysis techniques and their application in the food industry, with a view to providing a reference for technological innovation in the field of high-quality plant-based food processing.

The plant milk market has a promising future and flavor is a critical quality attribute of plant milk. The good flavors of plant milk such as milky, fruity, nutty, and cereal-like aromas are well-liked by consumers, while the undesirable flavors such as bitterness, bean-like odor, green odor, and mushroom-like odor severely limit the development of the plant milk industry. Based on the current state of development and future trends in raw material screening and processing technology for plant milk production and research on the flavor composition of plant milk, this paper summarizes the methods used for the extraction and identification of volatile substances from plant milk and the material basis of its flavor composition, highlighting the formation pathways of aroma and off-odor, the interaction between macromolecules and small molecules in plant milk, and the influential factors of and the regulatory strategies for the formation of aroma and off-odor in plant milk. This review is expected to provide scientific research ideas and strategies for maximizing the preservation of the good flavor of plant milk and avoiding the generation of undesirable flavors.

Flaxseed is one of the eight major oil crops in China, and flaxseed oil is a healthy vegetable oil rich in α-linolenic acid, which is highly favored by consumers. Volatile flavor substances are a key attribute affecting the quality of flaxseed oil and its popularity among consumers. This article provides a systematic overview of recent advances in the research on volatile flavor substances in flaxseed oil, with a focus on the techniques and methods for the extraction, analysis and detection of volatile flavor substances in flaxseed oil from the perspective of molecular sensory science, the material basis and aroma characteristics of volatile flavor in flaxseed oil, and the factors affecting the flavor formation of flaxseed oil. Moreover, it also summarizes the possible formation pathways of some key flavor substances during the processing of flaxseed oil. It is hoped that this review will provide a theoretical basis for improving the flavor of linseed oil.

In this study, the effects of different mass fractions of whey protein isolate (WPI) on the physicochemical properties, physical stability, rheological properties and microstructure of Antarctic krill oil (AKO, 30%, m/m)-in-water emulsion were compared and analyzed. The results showed that the mean particle size and zeta potential of AKO emulsion without WPI were 516.67 nm and −14.03 mV, respectively. As the mass fraction of WPI increased from 0% to 6%, the mean particle size of the emulsion decreased by 42.28% (P < 0.05), and the absolute value of zeta potential significantly increased by 18.05% (P < 0.05). The physical stability of the emulsion was obviously improved. Shear rheological test showed that the apparent viscosity of the emulsion increased with an increase in WPI mass fraction. Microrheological test showed that the introduction of WPI in the emulsion system slowed down the droplet movement speed, increased the elastic behavior, and decreased the fluidity. The microstructure observation showed that WPI addition caused the emulsion to form a more complete and uniform network structure, binding more lipid droplets to maintain the stability of the emulsion. The excessive addition (greater than 6%) of WPI caused the flocculation of the emulsion, thereby weakening its stability. Therefore, the addition of appropriate amounts of WPI can effectively improve the stability of AKO emulsion by reducing the particle size, increasing the charge repulsion force of lipid droplets, and enhancing the viscoelasticity and protein network structure binding. This study is expected to provide guidance for constructing high-load and high-stability AKO emulsion system and broadening its application in health foods.

DHA藻油是补充ω-3多不饱和脂肪酸的重要非动物来源，但因其自身水溶性差、易氧化产生不良风味等特点，极大约束了其摄入途径。据此，采用高压微射流技术与逐层沉积技术（LBL）制备负载DHA的亚麻籽胶（FG，质量分数为0.4%）-紫苏分离蛋白（PPI，质量分数为0.225%）双层乳液，研究Ca2+添加量（0%～0.5%）对上述双层乳液体系稳定性的影响；同时，采用INFOGEST体外模拟消化模型，探究PPI-DHA藻油单层乳液、FG-PPI-DHA藻油双层乳液、Ca2+-FG-PPI-DHA藻油双层乳液中DHA的消化特性，以及上述3种体系递送虾青素的效率，并通过监测其在消化过程中粒径分布、电荷特性及微观状态变化等解释其内在机理。结果表明：DHA藻油双层乳液储藏20 d后，未添加Ca2+的双层乳液的粒径从10.4 μm降低至4.3 μm，Zeta-电位从-23 mV降低至-33 mV，Ca2+添加量为0.4%的双层乳液的粒径和电位未发生显著变化，乳液液滴分布均匀，无分层、絮凝、沉淀现象；DHA藻油双层乳液储藏20 d后，添加Ca2+的双层乳液的Turbiscan抗重力稳定性指数（TSI）较未添加Ca2+的双层乳液有明显改善；3种乳液体系模拟消化过程中，游离脂肪酸释放量分别为68.88%、50.84%、52.32%，虾青素生物可及性分别为47.42%、12.54%、966%。说明添加Ca2+有利于DHA藻油双层乳液的稳定储藏，但对消化过程中脂肪酸与虾青素的释放具有一定迟缓效果，研究结果可为设计靶向递送体系提供重要理论依据。DHA algae oil is an important non-animal source for supplementing omega-3 polyunsaturated fatty acids (ω-3 PUFA), but due to its poor water solubility and easy oxidation to produce bad flavor, its intake route is greatly restricted. Accordingly, high-pressure micro-jet technology and layer by layer (LBL) were used to prepare DHA-loaded flaxseed gum (FG, mass fraction 0.4%)-perilla protein isolate (PPI, mass fraction 0.225%) double-layer emulsion, focusing on the effect of calcium ion addition (0%-0.5%) on the stability of the above-mentioned double-layer emulsion system. At the same time, the INFOGEST in vitro simulated digestion model was used to explore the digestion characteristics of DHA in PPI -DHA algae oil single-layer emulsion, FG-PPI -DHA algae oil double-layer emulsion, and Ca2+-FG-PPI -DHA algae oil double-layer emulsion, as well as the efficiency of astaxanthin delivery by the above three systems, and its internal mechanism was explained by monitoring its particle size distribution, charge characteristics and microscopic state changes during the digestion process. The results showed that after 20 d storage of the DHA algae oil double-layer emulsion, the particle size and Zeta-potential of the double-layer emulsion without Ca2+ decreased from 10.4 μm to 4.3 μm, from -23 mV to -33 mV, respectively, but for the double-layer emulsion with 0.4% Ca2+ addition，the particle size and Zeta-potential did not change significantly, the emulsion droplets were evenly distributed, and there was no delamination, flocculation, or sedimentation.After 20 d storage of the DHA algae oil double-layer emulsion, the Turbiscan anti-gravity stability index (TSI) of the Ca2+-added double-layer emulsion was significantly improved compared with the non-Ca2+-added double-layer emulsion. During the simulated digestion process of the three emulsion systems, the release of free fatty acids in the three systems was 68.88%, 50.84% and 52.32% respectively, and the bioavailability of astaxanthin in the simulated digestion process was 47.42%, 1254% and 9.66%, respectively. It shows that the addition of Ca2+ is beneficial to the stable storage of the DHA algae oil double-layer emulsion, but has a certain retarding effect on the release of fatty acids and astaxanthin during the digestion. The research results provide an important theoretical basis for designing a targeted delivery system.

通过模拟加热(180 ℃加热15、30 min)及家庭烹饪（炒青菜）过程，研究了一种富含不饱和脂肪酸、n-6/n-3脂肪酸比例适宜且有益脂质伴随物含量丰富的配方食用油的加热及烹饪稳定性。结果表明：配方食用油在加热或烹饪青菜时其酸值、过氧化值略有上升，但均远低于GB 2716—2018的规定；加热和炒菜过程中不会造成反式脂肪酸含量的增加，且苯并(a)芘含量远低于国标限量，说明在加热和炒菜过程中该配方食用油能够保持安全稳定；此外，配方食用油脂肪酸组成在加热或烹饪前后变化不大，n-6/n-3脂肪酸比例稳定，生育酚和总酚含量在加热和烹饪后下降幅度在35%以内，植物甾醇含量下降约12%。由此可知，配方食用油能够在常规家庭烹饪过程中保持稳定，是一种日常补充n-3多不饱和脂肪酸和有益脂质伴随物的有效途径。The heating and cooking stability of a formula oil enriched in unsaturated fatty acid, appropriate ratio of n-6 to n-3 fatty acids and beneficial lipid concomitant was investigated by simulating the heating(15,30 min at 180 ℃)process and home cooking(stir-frying vegetables) process. The results showed that the peroxide value and acid value of the formula oil increased slightly after heating and cooking, and both of them were below the limit of GB 2716-2016. Besides, the content of trans fatty acids did not increase during heating and cooking, and the content of benzo(a) pyrene was far below the national limit, indicating that the formula oil was stable during heating and cooking process. The fatty acid composition and the ratio of n-6 to n-3 fatty acid of the formula oil almost kept constant after heating and cooking. The contents of tocopherol and polyphenol decreased within 35%after heating and cooking, while that of phytosterol decreased by about 12%. Overall, the formula oil was stable in family cooking process, and it was a good way to supply n-3 polyunsaturated fatty acid and beneficial lipid concomitant.