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proportion of this amino acid. GABA, a non-protein amino acid, 这个比例的氨基酸。丁酸，一种非蛋白质氨基酸， possesses well known physiological functions such as neurotransmission, 具有众所周知的生理功能，如神经传递， induction of hypotension, and diuretic and tranquilizers 诱导性低血压，和利尿剂和镇静剂 effects (Jakobs et al., 1993; Guin Ting Wong et al., 北京世博翻译公司2003). 影响（雅科布斯等人。，1993；因皇廷等人。，北京世博翻译公司2003）。 This paper reports on investigations aimed at developing and 本文报告的调查，旨在开发和 characterizing a fermented goats’ milk enriched of GABA and ACEinhibitory 表征发酵山羊'牛奶富含 γ-氨基丁酸和 aceinhibitory peptides through the use of selected multiple starter 肽通过使用选定的多个启动器 cultures. 文化。 北京世博翻译公司2. Materials and methods 北京世博翻译公司2。材料与方法 北京世博翻译公司2.1. Raw milk, microorganisms and ingredients 北京世博翻译公司2.1。原料乳，微生物和成分 Milk samples were collected when goats (Ionica breed) were 9– 牛奶样品收集当山羊（ionica 品种）9– 11 weeks in lactation and analysed for chemical composition. 11 周的哺乳期和分析化学成分。 Protein content was determined by the Kjeldahl method (AOAC, 蛋白质含量测定凯氏定氮法（原， 北京世博翻译公司2003a) using a VELP DK6 heating digester and a VELP UDK 130 北京世博翻译公司2003 年）使用维尔普 dk6 加热蒸煮和维尔普虚幻引擎开发包 130 distillation system (VELP Scientifica, Usmate Milan, Italy). Fat was 蒸馏系统（维尔普 scientificaUs mate，米兰，意大利）。脂肪的 determined by the Gerber method, according to Stelios and 确定的方法，根据斯泰利奥斯和 Emmanuel (北京世博翻译公司2004). Lactose was determined by an enzymatic 艾曼纽（北京世博翻译公司2004）。乳糖是所确定的酶 method, using the Megazyme (Megazyme International Ireland 方法，使用 megazyme（megazyme 国际爱尔兰 Ltd., Bray, Ireland) kit K-LACGAR. Ashes were determined by dry 公司，布雷，爱尔兰）k-lacgar 套件。灰烬测定干 ashing the samples in a muffle furnace at 550 C (AOAC, 北京世博翻译公司2003b). 灰化样品在马弗炉在 550 摄氏（化学家，北京世博翻译公司2003 年）。 The pH, determined by a pH meter (Beckmann F40, Beckmann, RIIC 值，确定一个值（贝克曼 F，贝克曼，riic Ltd, High Wycombe, UK) was ca. 6.55 and titratable acidity, determined 有限公司，海威科姆，英国）约为 6.55，可滴定酸，确定 according to the AOAC Official Method no. 9北京世博翻译公司20.1北京世博翻译公司24 (AOAC, 根据官方 9北京世博翻译公司20.1北京世博翻译公司24 号（原测定方法， 北京世博翻译公司2003c), was 0.1北京世博翻译公司25% (g of lactic acid/100 g of milk). Goats were 软件），0.1北京世博翻译公司25%（克乳酸/100 克牛奶）。山羊 grazed on pasture and milking was carried out twice daily, manually. 在牧场放牧、挤奶进行每天两次，手动。 After milking, the milk was immediately refrigerated to ca. 4 C 后挤奶，牛奶是立即冷藏约 4 丙 and within 3 h stored in a freezer (Ignis ICF410, Whirlpool, Siena, 3 小时内和储存在冰箱（1icf410，惠而浦，锡耶纳， Italy) at 北京世博翻译公司20 C until used. 意大利）在 北京世博翻译公司20 直到使用。 Lactic acid bacteria (S. thermophilus CR1北京世博翻译公司2, Lactobacillus casei 嗜热乳酸菌（Cr 1北京世博翻译公司2，干酪乳杆菌 LC01, Lactobacillus helveticus PR4, L. acidophilus 北京世博翻译公司2949 and Lactobacillus lc01pr4，瑞士乳杆菌，嗜酸乳杆菌 北京世博翻译公司2949 和乳酸菌 plantarum 1北京世博翻译公司288) belonging to the Culture Collection of the 1北京世博翻译公司288）属文化的收集 Department of Plant Protection and Applied Microbiology, 植物保护系和应用微生物学， University of Bari, were routinely propagated in M17 (Oxoid Ltd, 巴里大学，经常被传播（蛋白多有限公司， Basingstoke, Hampshire, UK) (streptococci) or MRS (Oxoid Ltd, 贝辛斯托克，汉普郡，英国）（链球菌）或夫人（蛋白有限公司， Basingstoke, Hampshire, UK) broth (lactobacilli) at 30 C (L. casei 贝辛斯托克，汉普郡，英国）肉汤（乳酸菌）在 30℃（L 干干酪 LC01 and L. plantarum 1北京世博翻译公司288) or 37 C (S. thermophilus CR1北京世博翻译公司2, L. lc01 和植物乳杆菌 1北京世博翻译公司288）或 37℃（嗜热链球菌 Cr 1北京世博翻译公司2，L . helveticus PR4 and L. acidophilus 北京世博翻译公司2949). 瑞士 pr4 和嗜酸乳杆菌 北京世博翻译公司2949）。 Sodium caseinate was produced from goats’ milk as described 酪蛋白酸钠生产的山羊'牛奶的描述 by Minervini et al. (北京世博翻译公司2003). The pectin preparation was provided by 由梅诺菲尼等人。（北京世博翻译公司2003）。果胶的制备提供了 Lippolis srl (Putignano, Bari, Italy) and contained ca. 115 g kg 1 黎波里斯里亚尔（PUTIGNA NO，巴里，意大利）和包含约 115 克公斤 1 moisture and 770 g kg 1 pectin; the degree of esterification for 水分和 770 克公斤 1 果胶的酯化度为； pectin was ca. 63% (HMP). Threonine was purchased from Sigma 果胶是约 63%（公司）。苏氨酸购买西格玛 Chemical Co. (Milan, Italy). 化工有限公司（米兰，意大利）。 北京世博翻译公司2.北京世博翻译公司2. Manufacture of fermented milks 北京世博翻译公司2.北京世博翻译公司2。生产发酵乳 Taking into account that it is difficult to manufacture a fermented 考虑到这是难以制造发酵 goats’ milk endowed with a good consistency, at the beginning of 山羊奶具有很好的一致性，在开始 the experimental work some trials were carried out with the aim to 实验工作进行了一些试验的目的 set a protocol for manufacturing a product with a good consistency 建立一个协议制造的产品具有很好的一致性 coagulum. All the fermented milks (FMs) were manufactured 凝结物。所有的发酵奶（柔性制造系统）制造 according to the following steps: addition of sodium caseinate 按照下列步骤：添加酪蛋白酸钠 (15.0 g kg 1) and pectin (北京世博翻译公司2.5 g kg 1) to improve coagulum consistency, （15 克公斤 1）和果胶（北京世博翻译公司2.5 克公斤 1）提高凝固的一致性， and of threonine (0.8 g kg 1) to increase the concentration of 和苏氨酸（0.8 克公斤 1）增加浓度 acetaldehyde; heat treatment (70 C for 30 min, while agitating) to 乙醛；热处理（70 为 30 分钟，而搅拌）对 inactivate non-spore-forming pathogenic and spoilage microorganisms, 灭活孢子形成的致病微生物和腐败， and to improve the distribution of the ingredients; rapid 和改善分配的成分；快速 cooling to 40 C and inoculation with a single- or mixed-starter 冷却到 40 摄氏接种单-或 mixed-starter culture, as indicated in Table 1. In details, heat treatment of milkwas 文化，如表 1。在细节上，热处理 milkwas conducted in a bain-marie, while milk temperature was monitored 在水浴，而牛奶温度监测 by inserting a penetration probe of a Dualtemp thermometer (TFA 插入一个贯穿探针的 dualtemp 温度计（三氟 Dostmann Ltd, Reicholzheim, Germany). The time needed for the dostmann 有限公司，reicholzheim，德国）。所需的时间 center of a 500 ml milk bulk to reach 70 C was ca. 10 min. Subsequently, 中心的 500 毫升牛奶体积达到 70 摄氏约 10 分钟。随后， heat-treated milk was rapidly cooled (ca. 5 min) to 40 C in 热处理牛奶是迅速冷却（约 5 分钟）40 丙型 a ice-bath. Starter lactic acid bacteria were prepared as follows: 北京世博翻译公司24 h 一个冰浴。乳酸菌发酵制备如下：北京世博翻译公司24 小时 old cells cultured inM17 or MRS broth were used to inoculate (1%, v/ 老细胞培养 inm17 或肉汤被用来接种（1%，5 / v) reconstituted 10% (w/w) skim milk from Oxoid Ltd. (Basingstoke, 五）重组 10%（瓦特/瓦）脱脂乳蛋白（从公司网站， Hampshire, UK). Cell growth in reconstituted skim milk was 汉普郡，英国）。细胞生长在改组脱脂牛奶 determined by measuring the optical density of the culture at 通过测量光密度的文化 600 nm (Ultrospec 3000, Pharmacia Biotech, Uppsala, Sweden) 600 纳米（ultrospec3000，溴酚蓝，乌普萨拉，瑞典） after clarification by addition of sodium citrate (Exterkate, 1984). 澄清后，通过添加柠檬酸钠（exterkate，1984）。 One single preculture for each starter was prepared and used, even 一个单一的预为每个启动准备和使用，即使 for mixed started fermented milks. Twelve h-cultured skim milk 混合开始发酵奶。十二 h-cultured 脱脂牛奶 was used to inoculate (1%, v/v) goats’ milk to obtain approximately 被用来接种（1%，体积比）山羊'牛奶获得约 7.0 log cfu g 1. Inoculated milkwas stirred, bottled and incubated at 7 日志祖 1 克。接种 milkwas 搅拌，瓶装和培养在 30 or 37 C, depending on the optimal temperature of the lactic acid 30 个或 37，取决于最佳温度的乳酸 bacteria inoculated (Table 1), until pH 4.6 was reached. Finally, FMs 细菌接种（表 1），直至达到 4.6。最后，柔性制造系统 were cooled to 4–6 C and stored at 4 C. 被冷却到 4–6 和储存在 4C Three batches of goats’ milk were collected on different days and 三批山羊'牛奶收集不同天和 on each occasion were used for the manufacture of the eight types 每一次被用于制造的八种类型 of FM. 调频。 Table 1 表1 Lactic acid bacteria used as starters, incubation temperature and time needed to 乳酸菌作为起动器，孵化温度和所需的时间 reach pH 4.6 for different fermented goats’ milks. 达到 4.6 不同发酵山羊奶 Lactic acid bacteria Incubation 乳酸菌培养 翻译公司 (责任编辑：北京翻译公司) |