Plant foods Animal foods Products section 1 Cereal

Plant foods Animal foods Products

section 1 Cereal grains, legumina • Molds and mycotoxin(aflatoxin ) 曲霉、毛霉、根霉 青霉和镰刀菌等 Corn and peanut • Prevent contamination ümoisture 安全水分： 粮谷 12~14%， 豆类 10~13% AW≤ 0. 7 üTemperature üComponent of gas: O 2<2% CO 2>40~50% üChemical method: 环氧乙烷 • detoxification

vegetables and fruits • Learn by yourself

section 2 Meat, poultry, fish and products

一、Meat and meat products • spoilage腐败变质 four phases rigor mortis(僵直）： Fresh meat glycogen in muscles p. H 7. 0~7. 4 anaerobic condition lactic acid ATP disappearance Ph 5. 4 myosin contraction Ageing后熟： p. H继续下降 营养学意义 牛、羊肉 猪、鸡肉 鱼 Temperature ： 36 ℃ 12 h 4℃ 1~3 days Glycogen content: Lactic acid: act as mild preservative卫生学意义

secton 3 Milk and milk products • Spoilage: 乳素（lectcynin)，抑菌作用 0℃ 48 h 37℃ 2 h 挤出牛奶，及时冷却 微生物污染，繁殖 lactose lactic acid , 酸味，p. H protein凝固 protein decompose

Milk processing sequence 鲜奶生产卫生 • Clarification净化: centrifugal clarifier： remove sediment body cells, some bacteria filtration过滤法 • Homogenization均质化： fat globules(0. 1~20 um in diameter) gather into clumps and rise subdivide to small size

• Pasreurization: aim: rid any disease-producing organisms destroy lipase(脂肪酶） and other enzymes LTHT(low temperature long time): 62℃ for 30 min: mycobacterium tuberculosis no -spore-forming bacterium 63 ℃ for 30 min: coxiella burnetii causing Q fever HTST(high temperature short time): 75 ℃ holding for not less than 15 sec UHT(ultrahigh-temperature process): 137. 8 ℃ 2 sec bacterium and spore Others: 煮沸消毒 蒸汽消毒

• Cooling and packaging: pasteurized milk is not sterile, so quickly cooled 4 -6 ℃ paper cartons, plastic jugs, bottle 奶贮运的卫生 低温，保持运输 具及容器的卫生

secton 6 fats, oils, and related producted • Fats : solid at room temperature vegetable: cocoa butter，coconut oil animal: lard from hogs, tallow from beef butterfat from milk • Oils : liquid vegetable: soybean，peanut，corn， sunflower，cottonseed，olive(salad) fish : cod(鳕）liver oil ，menhaden(鲱鱼）， whale oil margarine(人造黄油）、代可可脂

Production and processing methods • Rendering: 煎熬提取（脂肪） lard • Pressing or expelling压榨法： heat compression: cooked slightly to break down cell structure and to melt fat easier cold compression: 出油率低，保持蛋白质理化性质 • Solvent extraction浸出法： 6号溶剂或 hexane（ 正己烷） 艺先进，出油率高。我国溶剂残留量 ≤ 50 mg/kg。WHO <10 mg/kg • 水化法：小磨麻油 用水将油料中的油脂取代出来

毛油: 组织残渣和杂质 水化 碱炼：破坏有毒物质（gosspy AF) 精炼油：Refining精炼 除杂、脱酸(free fatty acid+Na. OH)、 Degumming脱胶: phospholipids or fat-protein complexes, gummy , wetted with water, insoluble in the oil , gain phospholipid lecithin(卵磷脂) Bleaching 脱色: plant pigments, removed by passing over charcoal or adsorbent clays Deodorization脱臭: odorous compounds injecting steam into the fat (240 ℃ ，水蒸气） 老化(30℃ 7~8 ℃, 高熔点甘油酯结晶） 色拉油

3. factors influencing rate of lipid oxidation in foods ＊ fatty acid composition arachidonic linoleic acids (40: 20: 1) ＊ free fatty acids oxidize at a greater rate when free than when esterified to glycerol ＊ oxygen concentration ＊ temperature ＊ trace metals: catalysis ＊ Radiant energy: visible ultraviolet γ-radiation

ü 4. 评价油脂酸败的常用指标： § acid value/AV酸价：refers to a measure of free fatty acids present in a fat. defined as the number of milligrams of potassium hydroxide necessary to neutralize 1 g of the fat or oil. 精炼油≤ 0. 5，棉籽油≤ 1 § peroxide value/POV过氧化值: degree of oxidation peroxides can liberate iodine from potassium iodide. Expressed in terms of milliequivalents of iodine per kilogram of fat. Early stages of oxidation, POV reach a peak and then decline. WHO ≤ 10 meq/kg

§ carbonyl group value/CGV羰基价： total: aldehydes or ketones react with 2, 4 dinitrophenylhydrazine meq/kg CGV≤ 10 meq/kg volatile: lower moleculor weight volatile carbonyl compounds influence on flavor recovered by distillation or reduced pressure, determined by reaction with reagents or by chromatographic methods § 丙二醛含量：猪油≤ 2. 5 mg/kg 可随氧化不断增加 others: Iodine Value碘价: degree of unsaturation of fatty acid. number of grams of iodine absorbed by 100 g of fat saponification value皂化价、physical characteristic

维生素A 强化食用油 迎面而来 ü ü ü Why choose oils? Package、marker Price Stability Safety intake: 25%RNI

vinegar • 生成 艺 • 卫生及管理 material zymogen 发酵菌种 package

secton 9 others • honey ★ component ★ 卫生及管理： antibiotic residual zinc poison honey 毒蜜 Clostridium botulinum toxin 肉毒梭菌

cake • material: • • food supplies fat and oil maltose饴糖 egg and egg products additive water 生成过程 糕点出场前的卫生及质量管理

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