【作者】 周春红；

【导师】 阚建全；

【作者基本信息】 西南大学 ， 食品科学， 2011， 硕士

【摘要】 竹笋(Bambooshoot)是禾本科(Poaceae)竹亚科(Bambusoideae)植物的新生芽,历来以高纤、低脂、营养丰富的“寒土山珍”著称。其中,大叶麻竹笋(Dendrocalamus latiflorus)是丛生竹笋的一种,适应性广,产量高,近几年来得到广泛发展,但它在腌制过程中出现了特殊的臭味,严重影响了它的商品性。同时,我国虽为竹笋的生产和消费大国,但对竹笋品质的基础性研究还很不够。本论文基于此问题,将致力于大叶麻竹笋腌制加工过程中品质变化的研究,为麻竹笋中的挥发性成分和臭味物质的研究提供可行的方法。本文以重庆产大叶麻竹笋为原料,采用现代的仪器分析检测技术,系统深入地分析研究了大叶麻竹笋腌制过程中营养成分的变化、质地与细胞结构的变化,并结合感官分析对大叶麻竹笋在腌制加工过程中的挥发性成分及臭味物质也进行了一定的研究,旨在为提高大叶麻竹笋加工产品的品质提供试验数据。主要研究结果如下：(1)大叶麻竹笋在腌制过程中,随着时间的增加,蛋白质含量逐渐降低,降低的趋势为发酵性腌制>非发酵性腌制>自然发酵；鲜样中可溶性糖的含量为0.1226%,自然发酵后的麻竹笋中可溶性糖的含量下降了91.84%；非发酵性腌制的两个样品分别降低了85.32%,87.93%；发酵性腌制中漂烫与未经漂烫的两种产品可溶性糖含量分别下降了98.12%,98.21%；发酵与非发酵性腌制产品在腌制过程中,纤维含量都呈现递增趋势；腌制时间越长,维生素C的损失越大。(2)采用氨基酸自动分析仪的方法测得,新鲜的大叶麻竹笋中氨基酸总量为16.35g/100g。在17种氨基酸中,天冬氨酸的含量最高,含量最少的是胱氨酸。人体必需氨基酸含量占氨基酸总量的百分数在自然发酵和腌制加工后都有所增长,鲜味和甜味氨基酸的百分含量下降,苦味氨基酸有所增加。腌制后的大叶麻竹笋中钙和钾的含量都高于新鲜的竹笋,而磷、锌以及铁的含量却降低了,其中磷的损失最明显。(3)大叶麻竹笋在腌制过程中,经过非发酵性腌制的两组样品中原果胶的含量分别降低了61.7%和48.93%；发酵性腌制中漂烫与未经漂烫的两种产品分别降低了68.08%,63.8%。水溶性果胶的含量总体上出现上升趋势,也有短暂下降。大叶麻竹笋的硬度值随时间的延长呈现下降趋势。经过自然发酵的竹笋品质变劣最快,硬度值急剧下降。竹笋的脆度值也呈现下降趋势,但降到一定程度就相对稳定下来。从微观结构来看,所有经过腌制的竹笋,细胞组织都发生了失水。非发酵性腌制样品的纤维比发酵性腌制的长。另一方面,漂烫会引起细胞组织结构肿大造成硬度降低,未经过漂烫处理的竹笋组织纤维排列更整齐,井然有序。(4)在感官分析中,综合口感最好的是鲜样,其次是经过漂烫的非发酵性腌制产品。在质地方面,非发酵性腌制的竹笋脆嫩度优于发酵性腌制的竹笋。经过漂烫的样品组在色泽上比未经漂烫的样品组保持得更好。在滋味方面,自然发酵的酸味和苦涩味最重,品质不好。在气味方面,大叶麻竹笋在腌制后都产生了特殊的臭味。(5)经过GC-MS分析,从新鲜的麻竹笋中鉴定出了37种化合物,占总组分的92.37%；在非发酵性腌制的未漂烫样品中鉴定出了52种化合物,占总组分的99.95%；在发酵性腌制的未漂烫样品中鉴定出了47种化合物,占总组分的93.78%。(6)在新鲜大叶麻竹笋的样品中,经GC-O试验测定发现了16种带有明显的风味特征的物质；青草味、涩味是新鲜大叶麻竹笋的主要风味,己醛、苯甲醛是大叶麻竹笋的两种特征性风味物质。在非发酵性腌制的大叶麻竹笋样品中,测定发现了23种带有明显的风味特征的物质；青草味、涩味及其臭味是大叶麻竹笋非发酵性腌制中的主要风味；对臭味贡献最大的物质主要有四种,即丁酸,戊酸,己酸,4-甲基苯酚。在发酵性腌制的大叶麻竹笋样品中,鉴定发现了19种带有明显风味特征的物质；青草味、辛涩味及其臭味也是大叶麻竹笋在发酵性腌制中的主要风味；对臭味贡献最大的物质主要有3种,即己酸,二甲基丁酸,4-甲基苯酚。结论：本研究表明,大叶麻竹笋在腌制加工过程中,蛋白质、可溶性糖、维生素C的含量呈下降趋势,粗纤维的含量增加。非发酵性腌制在质地和感官方面都优于发酵性腌制。经GC-MS-O测得臭味物质有四种,即丁酸,戊酸,己酸,4-甲基苯酚。更多还原

【Abstract】 Bamboo shoot is the new bud in the plants of Poaceae Bambusoideae,which is always known as "treasure in cold soil" beacause of high-fiber, low-fat, rich nutrition. Dendrocalamus latiflorus is a woody bamboo shoots, wide adaptability, high output, which has been widely development in recent years. But it appeared special odor in salted process, influence with its commercial performance. At the same time, our country is the production and consumption for the bamboo shoots, but the basic research about its quality is not enough. Based on this problem, this paper will be devoted to the quality change of Dendrocalamus latiflorus in salted processing, to provide available methods for the research about volatile organic compounds and odor compoundsTaking Dendrocalamus latiflorus produced in Chongqing as raw materials, adopting the modern instrument analysis of testing technology, it analyzed the process of flax bamboo shoots salted nutritional variation, texture and cellular structure change, and combining the senses of hemp bamboo shoots analysis of volatile organic compounds and stink material research, the main research results are as follows:(1) The Dendrocalamus latiflorus in salted process, as time increases, protein content gradually reduced; Reduce trend:the fermentation of pickled> unfermentation of pickled> natural fermentation; Fresh kind contents of soluble sugar content is the 0.1226%, natural fermentation in the Dendrocalamus latiflorus after the content of soluble sugar shoot down 91.84%; The fermentation of pickled two samples respectively reduced of 85.32%,87.93%; Fermentation salted two products of soluble sugar content decreased 98.12%,98.21%. In salted process, fiber content have been increasing; The longer pickle, Vc loss is bigger.(2) The amino acid in fresh bamboo shoots in total to 16.35 g/100g,17 kinds of amino acids, Aspartic acid content of the content of the highest, at least relative is Cystine. The human body essential amino acid content the percentage of total of amino acids in natural fermentation and salted processed are increased, and freshness and sweet, bitter amino acid increased decline. Pickled process changes of mineral elements for:calcium and potassium content is higher than the fresh bamboo shoots, and phosphorus content, containing zinc and iron content amount is decreased, the loss of the most obvious phosphorus.(3) The Dendrocalamus latiflorus in salted process, after the fermentation of pickled, the content of pectin the two groups of samples, down 61.7%,48.93%; Fermentation of two groups of sexual salted 68.08% 63.8% reduced, respectively. The content of water-soluble pectin rising trend in general, also have appeared briefly drops. Its hardness value has declined. After natural fermented bamboo shoots quality tended to be the fastest. Bamboo shoots dawolong declines in value to a certain stage, but is relatively stable. Judging from microcosmic structure, all through the bamboo shoots, salted cells have happened to the water loss. Not fermentation of two groups of sexual salted, their fiber longer, salted and ferment sex fiber length less than some. Bleaching hot can cause cellular structure enlargement causes rigidity reduced. Without bleaching hot processing bamboo shoots organization fibres were more clean and orderly, cell-to-cell adhesion bigger.(4) Sensory analysis, comprehensive palate best fresh kind, followed by the drift hot salted products of fermentation. Texture, the fermentation of pickled bamboo shoots crisp degrees than salted fermented sex bamboo shoots. After bleaching hot sample group than the color without bleaching hot sample group keep better. In taste, natural fermentation sour and acerbity heaviest, not good quality. In that respect of smell, the Dendrocalamus latiflorus in souse hind indeed has a special odor.(5) After GC-MS analysis, from the fresh bamboo shoot out of the 37 identified compounds representing components of 92.37%; in non-fermentable blanching preserved samples are not out of the 52 identified compounds representing components of 99.95%; in the fermentation of preserved samples without blanching identified 47 compounds, 93.78% of the total composition.(6) In fresh samples, 16 species of flavoring characteristics substance was found by the GC-O test, grass flavor and astringency is fresh bamboo leaves the main flavor, the Dendrocalamus latiflorus has aldehydes and benzaldehyde,which is characteristic of the two kinds of bamboo flavour compounds. In the fermentation of pickled big leaf Dendrocalamus latiflorus found in the sample, the bamboo shoots evident determination of 23 kinds of flavoring characteristics substance, grass flavor and astringency and its smell is bamboo shoots the fermentation of pickled flavor of major. The biggest contribution to stink material basically has four kinds:butyrate, e acid, caproic acid,4-methyl phenol. In fermentation sex big leaf hemp bamboo shoots salted in the sample, evident determination found 19 kinds of material, grass flavor characteristics and its smell smell, zinn acerbity also is big leaf hemp bamboo shoots in the main flavor souse fermented sex. The biggest contribution to stink material basically has 3 kinds:caproic acid, two methyl butyrate, 4-methyl phenol.This research shows that Dendrocalamus latiflorus in salted the machining process, protein, soluble sugar, vitamin C content declined, crude fiber content increased. The fermentation of pickled in texture and sensory aspect is superior to the fermentation sex pickled. By GC-MS-0 measurement stink material basically has four kinds, namely butyrate, e acid, caproic acid, 4-methyl phenol.更多还原