【作者】 胡玉霞；

【导师】 叶兴乾；

【作者基本信息】 浙江大学 ， 食品科学， 2007， 硕士

【摘要】 雪菜，又名雪里蕻或雪里红(Brassica junce Coss.Var.multiceps Tsen et Lee)，是芥菜(Brassica juncea Coss.)的变种，也称为叶用芥菜。雪里蕻以长江流域以南的地区栽培较为普遍，不同的变种适应性各异。腌制雪里蕻在中国江浙一带非常的普遍，主要用于工业生产和家庭短期保藏，是重要的腌渍蔬菜。关于腌渍雪里蕻不同时间段的营养成分研究不多，本试验以宁波慈溪雪里蕻为原料，分别设置了两个萎焉程度，三种不同的腌渍方法(干腌、湿腌、接种乳酸菌腌渍)，对不同腌渍时间的理化、营养成分进行了系统研究，并对腌渍过程中酚酸物质的含量和抗氧化能力的变化作了分析，为腌渍蔬菜的综合利用提供了依据。研究主要结果有：1、对不同萎焉程度、不同腌渍方法雪里蕻的理化、营养性状分析得出：1)不同的腌渍方法，无论鲜样还是萎焉后的样品，盐含量均在腌渍第一周陡然上升到40％左右(干基含量)，与腌渍前达极显著差异(p＜0.01)，随后的腌渍阶段上升缓慢，以鲜样干腌上升量最大，在第八周达到52.35％，萎焉接种腌渍上升最少，为42.8％。总体来说，盐含量鲜样腌渍＞萎焉腌渍，干腌＞湿腌＞接种。2)腌渍初期，伴随着自然和接种两种发酵方式，酸度呈现出先上升趋势，在第2-3周达到最大值；随着腌渍盐含量的升高，酸度开始下降，7-8周酸度又略有上升。鲜样和萎焉样都以接种腌渍的峰值酸度最大，分别达到2.70％和2.83％，各腌法与腌渍前原料差异都极显著(p＜0.01)。腌渍中平均酸度接种腌渍=1.74％＞湿腌=1.50％＞干腌=1.48％，接种腌渍与另外两种腌渍方法没有显著差异。虽然鲜样的三种腌渍方法都在第3周达到最大酸度，但接种腌渍酸度高于湿腌和干腌。萎焉样同样接种酸度峰值最高，但晚于干腌和湿腌一周达到峰值。3)不同腌渍过程中蛋白质都呈现缓慢下降趋势，干腌、湿腌、接种腌三种腌渍方法中，鲜样蛋白质的量从28.56g／100gDW分别降至24.44、24.15、21.64g、100gDW其中干腌与腌前没有显著差异，湿腌差异显著(p＜0.05)，接种腌渍差异极显著(p＜0.01)；萎焉样由41.17g／100gDW分别降至35.06、24.57、25.62 g╱100gDW，其中干腌与腌渍前差异显著(p＜0.05)，湿腌、接种与腌前差异达到极显著(p＜0.01)，接种腌渍蛋白质下降快于另外两种腌渍方法。4)雪里蕻在腌渍过程中，氨基酸的含量随腌渍时间的增长而上升，在第6-7周达到最高值，峰值与腌前含量相比均达到极显著差异(p＜0.01)，随后下降。相同萎焉度不同腌渍方法、相同腌渍方法不同萎焉度之间没有显著差异。5)鲜样硝酸盐在不同腌渍过程中呈下降趋势，萎焉样除了干腌略有上升后才下降之外，也呈下降趋势。鲜样不同的腌渍方法在第二周分别下降了35％、31％和36.2％(由120.48 g／KgDW分别降为77.86、82.69和76.88g／KgDW)，差异均达极显著(p＜0.01)，接种腌渍下降最多。第3-4周有轻微回升，但与腌渍前差异仍极显著(p＜0.01)。萎焉样，腌渍前3周硝酸盐含量略高于腌渍前，差异不显著(p＞0.05)，第4周均降至与腌前差异显著(p＜0.05)，第5周降至极显著(p＜0.01)。6)亚硝酸盐在腌渍过程中有先上升后下降的趋势，在腌渍的第5周出现峰值，其中鲜样干腌、湿腌、接种三种腌渍方法峰值分别达到814.47、931.15、499.93mg／Kg，与腌前(44.32 mg／Kg)差异极显著(p＜0.01)；萎焉样干腌、湿腌、接种亚硝峰值分别为691.99、695.44、572.41 mg╱Kg，与腌前(58.89mg／Kg)差异极显著(p＜0.01)。两种萎焉度的接种腌渍峰值含量都低于干腌和湿腌，差异显著(p＜0.05)。7)腌渍前五周内，两种萎焉度原料干腌硝酸盐与亚硝酸盐相关性都不显著(p＞0.05)，鲜样另外两种腌渍方法硝酸盐和亚硝酸盐含量显著相关(p＜0.05)，萎焉样三种腌渍方法硝酸盐亚硝酸盐变化达到极显著相关(p＜0.01)。2、酚类活性物质含量的变化趋势为：1)总酚含量呈先升高后降低的趋势，不同萎焉度原料均以接种腌渍上升量最大，腌渍第2周鲜样和萎焉样分别从7.74 mg／g DW和3.96mg╱gDW上升至10.95mg／gDW和9.91mg╱gDW，上升量达41％和150％，差异极显著(p＜0.01)。2)没食子酸、原儿茶酸、对羟基苯甲酸、香草酸的含量在腌渍过程中呈上升趋势，与腌渍前差异极显著(p＜0.01)；而咖啡酸、香豆酸、阿魏酸、芥子酸在腌渍过程中则呈现先轻微上升后下降的趋势，与腌渍前差异极显著(p＜0.01)。各种腌法八种酚酸以芥子酸含量最高，平均323.33ug／gDW，没食子酸含量最少，平均20.93ug／gDW。3)腌渍过程中总酚酸的含量呈先上升后下降变化，同一腌渍方法，鲜样与萎焉样之间差异不显著(p＞0.05)；鲜样不同腌渍方法之间差异年不显著(p＞0.05)，萎焉样不同腌渍方法差异显著(p＜0.05)。3、对腌渍过程的雪里蕻体外抗氧化性研究表明：1)采用FRAP铁离子还原力、DPPH自由基清除和ABTS自由基清除三个体系腌渍后雪里蕻的体外抗氧化能力均有先上升后下降的趋势，且与腌前差异显著(p＜0.05)。2)蔬菜腌渍后抗氧化能力与其总酚含量相关极显著(p＜0.01)，三种抗氧化体系之间相关性也达到极显著(p＜0.01)。更多还原

【Abstract】 Potherb mustard (Brassica junce Coss. Var. multiceps Tsen et Lee), with Chinese name Red-in-Snow, is a cultivar of mustard(Brassica juncea Coss.). Potherb mustard also called leaf mustard, is widely cultured in the south of Changjiang River. Different cultivars have different adaptability. Pickled potherb mustard is very common in the district of Zhejiang, China, mainly because it can be preserved in long time in industry and house. However, most of pickled potherb mustard in the conventional food processing as products had low added value, and had no appropriately preserved time and methods. Moreover, the nutrition in potherb mustard, which was preserved in different time phases, was not clear. In the present research, the chemical characteristics and nutrients of the potherb mustard from Cixi, Ningbo during pickling was investigated. Mustard including withering and fresh materials was pickled by three different methods(dry-cured, wet-salted, lactobacillus inoculated-pickling). Chemical parameters such as nitrite and nitrate were analyzed, and phenolic acids and antioxidant activities were also evaluated.There are three main facts in this research:1 The effects of withering and pickling methods on the phytochemical properties of pickled mustard:1) In three pickling methods, using both withering and fresh material, salt content in pickled materials suddenly rose to about 40％in the first week of pickling (p＜0.01), compared to that of raw materials, then increased slowly. Dry-cured with fresh materials had the highest salt content in the eighth week, reached 52.35％. Inoculated-pickling using withering material had the lowest salt content of 42.8％. Generally speaking, the orders of the salt content were as follows: fresh pickling＞withering pickling; dry-cured＞wet salted＞inoculated-pickling.2) In the initial period of pickling, with the natural and the inoculated fermentation, the titratable acidity showed an increased tendency, and gave a maximum value in 2-3rd week, then decreased, probably causing by the higher concentration of salt; in 7-8th week, the titratable acidity rose slightly again. Inoculated-pickling with both fresh and withering material had the maximum titratable acidity value, respectively reached 2.0％and 2.83％. Compared with raw material, all values of the titratable acidity showed a significant (p＜0.01) increase. The average titratable acidity: inoculated-pickling(1.74％)＞wet-salting(1.50％)＞dry-curing (1.48％). However, three persevered methods had no significant differences (p＞0.01). Although the titratable acidity values of fresh pickling all reached maximum in the 3rd week, the value with inoculated-pickling was the higher than those of the other two treatments. Likewise, the values obtained with withering-pickling treatment were the same as those with fresh pickling. The most obvious differences between withering and fresh pickling were that the peak values of titratable acidity using withering materials occurred one week later than that of fresh pickling.3) In different preserve processes, the proteins all showed a slowly decreased trend. For example, dry-cured, wet-salted and inoculated-pickling of fresh materials reduced from 28.56 to 24.44, to 24.15, to 21.64g/100g of DW, respectively. Compared with raw material, dye-cured was not significantly different, wet-salted(p＜0.05) and inoculated-pickling(p＜0.01)were all significantly different. The three treatments of withering-pickled decreased from 41.17 to 35.06, to 24.57, to 25.62 g/100g of DW respectively, which were significant differences compared with raw materials: dye-cured (p＜0.05), wet-salted and inoculated-pickling (p＜0.01). The protein contents with the inoculated-pickling decreased more quickly than the other two pickles.4) In the processing of preserve, the free amino acid of potherb mustard increased with time, and had the highest values in the 6-7th week (p＜0.01), then decreased. There were no significant differences between different pickled methods.5) The nitrate contents in fresh pickling descended with time, whereas withering-pickled slightly rose, and then descended. In the 2nd week, the nitrate content of different pickled fresh materials decreased by 35％、31％和36.2％respectively(p＜0.01). The nitrate contents with withering-pickled treatment in 3 weeks increased slowly (p＞0.05), however, in the 4th week, the nitrate decreased significantly (p＜0.05).6) The nitrite contents in pickling showed a changing trend, and the highest values were found in the 5th week, then decreased The highest values of the nitrite in fresh materials using dry-cured, wet-salted and inoculated-pickling were 814.47、931.15、499.93mg/KgDW respectively, and the nitrite content in withering were 691.99、695.44、572.41 mg/KgDW respectively, which all were significantly different compared with raw materials(p＜0.01). The nitrite contents in both fresh and withering materials using dry-cured was higher than the other two treated methods (p＜0.05).7) The nitrate and nitrite contents in fresh materials using wet-salted and inoculated-pickling were significant negative correlation in 5 weeks (p＜0.05), whereas the nitrate and nitrite in the withered materials all showed significant negative correlation(p＜0.01).2 Changes of Phenols content in different preserved potherb mustards:1) The total phenols rose firstly, and then decreased. The total phenols contents with inoculated-pickling were higher than that in other two treatments, the values in fresh materials and withering ones increased from 7.74 to 10.95, 3.96 to 9.91 mg/gDW respectively (p＜0.01).2) Gallic acid, protocatechnic acid, p-benzoic acid and vinillic acid in the pickling increased (p＜0.01). Caffeic acid, p-cinnamic acid, ferulic acid and sinapic acid firstly increased, then decreased, which were significantly different compared with raw materials (p＜0.01). In all phenolic acids of pickling potherb mustard, the sinapic acid content was the highest(323.33ug/gDW), and the gallic acid was the lowest(20.93ug/gDW).3) Total phenolic acid, the sum of eight phenolic acids, were increased firstly in pickling, and then decreased. The total phenolic acid values using the same pickled methods with different raw materials showed no difference(p＞0.05); the valus using fresh materials but different pickled methods were similar(p＞0.05); the value using withering materials with different pickled methods were significantly different(p＜0.05).3 The results obtained by the antioxidant capability in vitro of pickling potherb mustards indicated that:1) The antioxidant capabilities were evaluated by FRAP, ABTS and DPPH, which all showed the same trend: an increase firstly and then descending. These data were all significantly different compared with raw materials(p＜0.05).2) The antioxidant capability correlated with total phenols significantly (p＜0.01), and three antioxidant systems all showed significantly dependent with another (p＜0.01).更多还原