【作者】 黄艾祥；

【导师】 陈宗道；

【作者基本信息】 西南大学 ， 农产品加工与贮藏工程， 2006， 博士

【摘要】 云南干腌火腿(以下简称云腿)历史悠久，具有瘦肉红似火、脂白有光泽、气味鲜香宜人、滋味浓郁独特、形似古乐“琵琶”等感官品质特征。云腿是云南省具有特色优势的食品加工产业和畜产品拳头产品，在国内外具有较高的知名度，研究其品质特征的形成规律和微生物对其品质特征形成的作用，对突破云腿理论研究的“瓶颈”和发展云腿产业意义重大。 1．云腿品质特征形成规律的研究 选择品种相同、质量约13kg的36条杂交猪后腿为原料腿，在控制条件下加工云腿，分别在原料腿、腌制中期(14d)、腌制末期(28d)、风干中期(20d)、风干末期(40d)以及发酵成熟30d、60d、90d、120d等9个工艺点随机抽取4条腿，分别取股二头肌(以下简称BF)、半膜肌(以下简称SM)以及股二头肌下部的脂肪为样品，对其感官指标(色、香、味、组织状态)、理化指标(水分、食盐、蛋白质、脂肪含量以及水分活度、pH值、色差值、剪切力值)、卫生指标(挥发性盐基氮、亚硝酸盐及脂肪酸价、脂肪过氧化值)和发酵期间的风味物质(游离脂肪酸、挥发性风味成分)等品质特征变化规律进行研究。结果表明： (1) 随着发酵期延长，火腿色、香、味、组织状态各项感官指标得分增加(P＜0.05)，具有更诱人的商品色泽，火腿风味逐渐浓郁。 (2) 加工过程中，火腿SM和BF的水分含量、水分活度呈逐渐下降趋势，其中SM较BF下降快，而与之相对应的食盐、蛋白质、脂肪含量则逐渐增加。控制适宜的水分含量和水分活度变化，对防止火腿腐坏变质、避免外部肌肉“结壳”，提高火腿质量有密切关系。云腿肌肉中挥发性盐基氮(TVB-N)、亚硝酸盐残留量以及脂肪酸价(AV)等卫生指标则随着加工期延长逐渐增高，其中TVB-N、AV值在腌制、风干期变化小，而进入发酵期后快速增加(由于温湿度增加、氧化加快)，而过氧化值(POV)则进入发酵期后含量有所下降，可能与其进一步降解成挥发性风味成分有关。亚硝酸盐残留量低于宣威火腿国家标准的规定(＜4mg／kg)，说明适量添加硝酸盐作为发色剂是可行的。云腿加工过程中BF和SM的pH值呈现高→低→高的变化趋势，特别进入发酵期后升高较快，主要是由于肉中糖原、蛋白质等降解所致。由于肌肉褐变和亚硝酸盐的发色作用，使色差值(L，a，b)发生一系列复杂变化，总体上呈现出低—高—低的缓慢变化趋势，其中BF的亮度(L)和红色度(a)一般高于SM，可能与其被氧化程度较低有关。剪切力值呈逐渐增大的趋势，主要原因是云腿加工期间食盐含量逐渐增加、水分含量逐渐减少，使其硬度和韧性逐渐增大，其中BF的剪切力值均高于SM，与其韧性较大有关。 (3) 应用高效气相色谱法(HPGC)测定了云腿发酵过程中BF和SM的9种游离脂肪酸变化(5次)，结果发现油酸、棕榈酸、亚油酸、硬脂酸是云腿发酵期间BF和SM中的主要游离脂肪酸；随着发酵期的延长，棕榈酸、硬脂酸等饱和脂肪酸相对比例增加，而油酸、亚油酸、亚麻酸等不饱和脂肪酸由于易氧化分解而相对比例逐渐降低。采用固相微萃取(SPME)方法和GC／MS系统提取和鉴定云腿发酵过程中BF和SM的挥发性风味成分(4次)，鉴定的风味成分可归类为：烷烯烃、醇类、醛类、酮类、酸类、酯类、酚类、芳香烃、含氧杂环化合物、含氮化合物、含硫化合物、含氯化合物等物质。随着发酵时间的延长，挥发性化合物种类呈增加更多还原

【Abstract】 Yunnan dry-cured ham is the major animal product industry in Yunnan province, with a long production history of over 300 years, it is reputed as one of the three most famous types of hams in China, and also one of the most famous dry cured hams in the world. Yunnan dry-cured ham characterized and famous for its fire-like red muscle, bright and clean fat, intense and delightful flavor, delicious and unique taste, and typical shape like Chinese musical instrument-pipa. Studies on the formation of traits and microbial roles of Yunnan dry cured ham is important for improving and developing Yunnan ham industry.l.Studies on the formation of Yunnan dry cured ham quality traitsExperimental Yunnan dry cured ham were processed by control processing technology with 36 hind legs weighed 13kg from crossbred pigs of local farm. M. Biceps Femoris （writing as BF in the follows） and M. semimembranosus （writting as SM in the follows） samples from 4 hams randomly taken at the green ham stage, salting stage（salting 14 days and 28 days）, drying stage（drying 20 days and 40 days）, and fermentation stage （30 days, 60 days, 90 days, 120 days） were used to analyze the changes of the following indexes, ①The changes of sensory index such as color, flavor, taste and texture,②The changes of physico-chemical indexes such as pH value, water activity（Aw） value, instrumental color patameters（Lightness-L, Redness-a, Yellowness-b）, shear force value and the content of moisture, NaCl, protein and fat in muscle, ③ The changes of hygienic indexes such as Total Volatile Basic Nitrogen（TVB-N）, NaNO₂ in muscle and Peroxidation Value（POV）, Acid Value（AV） in fat, ④The changes of flavor composition such as free fatty acids and volatile flavor compounds. The results showed that,（1）The sensory indexes such as color, flavor, taste and texture were improved with the development of ham fermentation （P<0.05）.（2）The physico-chemical indexes such as moisture, water activity in SM and BF descended with ham processing, whereas the content of NaCl, protein and fat in muscle were increased. Optimum moisture, water activity in SM and BF is important to control ham surface crust and improve the ham quality.（3）The hygienic indexes such as TVB-N, NaNO₂ in muscle and acid value in fat were increased with ham processing, the TVB-N and AV changed slowly in salting and drying stages, and increased rapidly in fermentation period, whereas the POV descended during ham fermentation. Residual content of NaNO₂ in ham was met with Xuanwei ham standard （<4mg/kg）. The changing trend of pH更多还原