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旨在为不同风味需求火锅底料的研究提供参考依据，通过消费者偏好分析和挥发性风味成分的含量与种类从6种牛油（3种市售牛油、未精炼牛油、脱胶牛油、精炼牛油）中筛选出最受消费者喜爱的牛油，并采用顶空固相微萃取结合气相色谱-质谱联用技术、香味提取物稀释分析法、气味活度值法、风味重组和风味缺失实验对其风味物质进行鉴定。结果表明：精炼牛油的消费者偏好平均得分最高且挥发性物质组成最丰富，其含有23种风味物质，包括醛类10种、酸类5种、杂环类4种、醇类3种和酮类1种；根据牛油风味物质的气味活度值，确定牛油的7种关键风味物质为（E,E）-2,4-壬二烯醛、（E）-2-辛烯醛、乙酸、2-戊基吡啶、辛醛、1-辛烯-3-醇和2-戊基呋喃，通过风味重组和风味缺失实验得出（E,E）-2,4-壬二烯醛、（E）-2-辛烯醛、乙酸和辛醛对牛油风味的贡献最大，2-戊基吡啶、1-辛烯-3-醇和2-戊基呋喃对牛油风味的贡献次之。综上，确认了牛油中7种关键风味物质，可为牛油产品风味的合理开发提供参考。In order to establish a foundation for researching the diverse flavour requirements of substances in hotpot bases, six types of beef tallow(three types of commercially available beef tallow, unrefined beef tallow, degummed beef tallow, and refined beef tallow) were used as materials, the most popular beef tallow was selected based on customer preference analysis and the content and type of volatile flavour components, and the flavour substances of the most popular beef tallow were identified using headspace solid-phase microextraction-gas chromatography - mass spectrometry, dilution analysis of flavour extracts, odour activity values, flavour reconstitution and flavour deletion experiments. The results indicated that refined beef tallow received the highest average score in the consumer preference analysis and had the most substantial chemical composition with 23 volatile substances including 10 kinds aldehydes, 5 kinds acids, 4 kinds heterocyclic, 3 kinds alcohols and 1 kind ketone compounds. Based on the odour activity values of beef tallow flavour substances, 7 kinds key flavour substances of beef tallow were identified as (E,E)-2,4-nonadienal, (E)-2-octenal, acetic acid, 2-pentylpyridine, octanal, 1-octen-3-ol and 2-pentylfuran. Flavour reconstitution and deletion experiments showed that (E,E)-2,4-nonadienal, (E)-2-octenal, acetic acid and octanal contributed the most to beef tallow flavour, followed by 2-pentylpyridine, 1-octen-3-ol and 2-pentylfuran. In conclusion, the 7 kinds key flavour substances are determined in the beef tallow, which can provide a reference for the rational development of beef tallow product flavours.

Following a fault on an AC transmission line for new energy， the fault response of the new energy power supply can influence the operation of distance protection. Therefore， leveraging the control strategy of the new energy power supply， this study delves into alternations in impedance， system power angle， and faulty electrical quantity prior to and post-fault. It also contrasts the performance of three distance protection mechanisms： phase polarization voltage， positive-sequence polarization voltage， and sudden magnitude variation. Given that the phase voltage drops to zero when faults occur at the line outlet， a non-responsive zone is inherent in the action area of phase polarization voltage distance protection mechanism. After a fault， the phase of the positive sequence voltage is influenced by control and shifts. This presents risks of refusal to trip during an internal fault and false tripping during an external fault for positive-sequence polarization voltage phase-sequence distance protection mechanism. Regarding the sudden magnitude variation distance protection mechanism， a fault can compel a shift in the compensated voltage phase due to control influences， which could result in protection refusal or false tripping. Using the real-time digital simulator （RTDS）， a system model demonstrating the transmission of new energy via AC lines is established. A simulation analysis of the performance of the three mechanisms is performed. The findings from the simulation align seamlessly with the theoretical scrutiny.

为调控煎炸过程中非挥发性甘油酯核心醛（GCAs）的生成,更合理地进行煎炸，通过高油酸葵花籽油煎炸薯条实验，探究煎炸方式、煎炸批次、煎炸温度以及油料比对10-氧代-8-癸烯醛酸酰基甘油三酯（10-oxo-8）和11-氧代-9-十一碳烯醛酸酰基甘油三酯（11-oxo-9）两种不饱和型GCAs生成的影响。结果表明：与间歇煎炸相比，连续煎炸产生更少的11-oxo-9，两种煎炸方式下10-oxo-8的含量总体上差异不大；每小时煎炸1批次薯条较煎炸多批次薯条生成的不饱和型GCAs更少，且煎炸油中的10-oxo-8和11-oxo-9含量与煎炸批次整体呈正相关；煎炸温度为160 ℃时较140 ℃和180 ℃生成的不饱和型GCAs更少；油料比为30∶ 1时，不饱和型GCAs总体含量较低。综上，为降低高油酸煎炸油中GCAs的含量，可采用连续煎炸方式并尽量控制煎炸批次，保持煎炸温度在160 ℃，控制油料比为30∶ 1。In order to regulate the generation of non-volatile glyceryl ester core aldehydes(GCAs) and make the frying process more reasonable, the effects of frying method, frying batch, frying temperature and ratio of oil to material on the production of two unsaturated GCAs, 10-oxo-8-decenoic aldehyde acyl triglyceride (10-oxo-8) and 11-oxo-9-undecenoic aldehyde acyl triglyceride (11-oxo-9), were investigated by frying French fries with high-oleic sunflower seed oil. The results showed that continuous frying produced less 11-oxo-9 than intermittent frying, and there was no significant difference in the content of 10-oxo-8 produced between the two frying methods; one batch of French fries fried per hour produced fewer unsaturated GCAs than multiple batches of French fries fried per hour, and there was a positive correlation between the content of 10-oxo-8 and 11-oxo-9 in the oil and the number of batches of French fries fried; the amount of unsaturated GCAs produced was lower when the frying temperature was 160 ℃ compared with that at 140 ℃ and 180 ℃; the amount of unsaturated GCAs produced was overall low when the ratio of oil to material was 30∶ 1. In conclusion, in order to reduce the content of GCAs in high-oleic frying oils, continuous frying can be used, the number of frying batches can be controlled as much as possible, the frying temperature can be maintained at 160 ℃ and the ratio of oil to material can be controlled at 30∶ 1.

烛果油富含1，3-硬脂酸-2-油酸甘油三酯（StOSt），是可可脂的理想改良剂。为探究烛果油在巧克力中的应用效果，以市售烛果油为研究对象，分析其组成特征，并研究其与可可脂复配的相行为及复配体系在经典黑巧克力中的抗霜性能。结果显示：烛果油中的StOSt（57.1%）和甘油二酯（6.65%）含量显著高于可可脂的（23.8%、4.48%），且烛果油中低熔点甘油三酯含量也高于可可脂的；烛果油在室温下的固体脂肪含量比可可脂低10~20百分点；当烛果油与可可脂按质量比9∶ 1复配时，其相应的巧克力抗霜性显著强于可可脂基巧克力，其中，合适的StOSt、POSt、POP三者比例（10∶ 3∶ 1）提高了油基的相容性，而适当的甘油二酯含量有助于保持相的均一性。综上，烛果油可应用于巧克力中以延缓巧克力起抗霜。Kokum fat is rich in StOSt and is an ideal modifier for cocoa butter. In order to explore the effect of its application in chocolate, commercial kokum fat was taken as the research object, its composition characteristics were analyzed, and the phase behavior of the compound with cocoa butter and the bloom resistance abilities of the compound system in classic dark chocolate were studied. The results showed that the contents of StOSt (57.1%) and diglycerol (6.65%) in kokum fat were significantly higher than that in cocoa butter (23.8%, 4.48%), and the content of low-melting triglyceride in kokum fat was also higher than that in cocoa butter. The solid fat content of kokum fat at room temperature was 10 to 20 percentage point lower than that of cocoa butter. Chocolate formulated with the binary fat containing 90%of kokum fat and 10% of cocoa butter exhibited desirable bloom resistance compared with cocoa butter based-chocolate. It was suggested that when the ratio of StOSt/POSt/POP was 10∶ 3∶ 1, the compatibility of fat phase could be improved, and desirable levels of diglycerides contributed to maintain phase homogeneity. In conclusion, kokum fat can be applied in the production of chocolate to delay the bloom of chocolate.

旨在为食品专用油脂的风味提升提供参考，采用顶空固相微萃取-气相色谱-质谱联用（HS-SPME-GC-MS）技术和感官评定分析黄油、椰子油、全氢化棕榈仁油、全氢化棕榈仁油硬脂、部分氢化大豆油和全氢化大豆油6种代表性食品专用油脂的挥发性成分和感官特征，并结合相对气味活度值（ROAV）及其聚类分析确定关键风味化合物。结果显示：椰子油的挥发性成分最为丰富，共鉴定出13个关键风味化合物，主要为内酯类、醛类化合物，椰子香和奶油香风味浓郁；黄油共鉴定出8个关键风味化合物，主要为内酯类、酮类和醛类化合物，具有果香、奶油香和青香；部分氢化大豆油共鉴定出6个关键风味化合物，主要为醛类和酮类化合物，主要呈果香、蜜蜡香、脂肪气味和奶油香；全氢化棕榈仁油、全氢化大豆油和全氢化棕榈仁油硬脂检出的关键风味化合物种类较少，分别为5个、2个和4个，主要为醛类和甲酯类/酸类化合物，主要呈果香风味和脂肪气味；感官评价结果和关键风味化合物分析结果存在一定联系。综上，6种食品专用油脂中，黄油、椰子油和部分氢化大豆油风味化合物较为丰富，具有突出的感官特征。Aiming to provide a reference for the flavor enhancement of food-special oils and fats, headspace solid-phase microextraction - gas chromatography - mass spectrometry (HS-SPME-GC-MS) and sensory evaluation were used to analyze the volatile components and sensory characteristics of six representative food-special oils and fats, namely butter, coconut oil, fully hydrogenated palm kernel oil, fully hydrogenated palm kernel oil stearin, partially hydrogenated soybean oil, and fully hydrogenated soybean oil, and combined with the relative odor activity value (ROAV) and its cluster analysis to identify their key flavor compounds. The results showed that coconut oil had the most abundant volatile components, and a total of 13 key flavor compounds were identified, mainly lactones and aldehydes, with a strong coconut and creamy aroma; butter had a total of 8 key flavor compounds, mainly lactones, ketones and aldehydes, with fruity, creamy and green aroma; partially hydrogenated soybean oil had a total of 6 key flavor compounds, mainly aldehydes and ketones, with fruity, beeswax, fat and creamy aroma; fully hydrogenated palm kernel oil, fully hydrogenated soybean oil and fully hydrogenated palm kernel oil stearin detected 5,2 and 4 of key flavor compounds respectively, mainly aldehydes and methy esters/acid, with fruity and fat aroma; the results of the sensory evaluation were related to the results of the analysis of the key flavor compounds to a certain extent. In conclusion, among the six food-special oils and fats, butter, coconut oil and partially hydrogenated soybean oil are richer in flavor compounds and have prominent sensory characteristics.

Nutrients in human milk are influenced by maternal diet, but it is still clear which type(s) of nutrients can be attributed to dietary changes. Most studies do not directly assess maternal diet or quantify the relationship between maternal diet and human milk composition. In this study, we retrieved and analyzed 24 observational studies, 5 crossover experimental studies and 11 parallel controlled experimental studies concerning ‘human milk/breast milk’, ‘nutrient’, ‘macronutrient’, ‘micronutrient’, ‘maternal nutrition’ and ‘maternal diet’ from the literature published before May 2022 in the PubMed and the Web of Science databases. It was found that in the diet of lactating mothers, fatty acids, especially polyunsaturated and trans fatty acids, and certain micronutrients, including fat-soluble vitamins (vitamins A and D), water-soluble vitamins (vitamin C) and trace minerals (iron, zinc and selenium), were closely related to their contents in human milk.