干姜和鲜姜水溶性风味物质的GC-MS研究

[目的]比较鲜姜与干姜水溶性风味物质的差异.[方法]以乙醇-水为溶剂分别提取鲜姜和干姜中的风味物质,以固相微萃取（SPME）顶空进样,采用GC-MS法测定2份提取液中风味物质的组成.[结果]鲜姜和干姜提取液中共鉴定出57种化学成分,其中有19种在鲜姜中未检测出来,有8种在干姜中未检测出来.鲜姜、干姜中的主要呈香呈味物质是倍半萜类物质,分别为α-姜黄烯、姜烯、α-法呢烯、β-甜没药烯、β-倍半水芹烯,但相对含量有显著差异,其中相对含量最高的为α-姜黄烯,分别为17.924％和25.402％.鲜姜、干姜水溶性风味物质的差异是：在2种提取液中相对含量大于3％的化学成分干姜比鲜姜少2种,分别是柠檬醛、枯茗醛,干姜没有的物质在鲜姜中的含量也很低,这些物质对姜的特征风味有较大的贡献.[结论]鲜姜提取液色泽透明、香气清新浓郁,无苦味,而干姜提取液色泽半透明,香气浓郁,但有苦味.     

肉风味前体物质与风味品质的关系研究进展

风味是重要的食用品质指标,良好的风味可引起人的食欲。肉的风味是烹调过程中风味前体物质、中间反应产物和降解产物经一系列复杂的化学反应形成的。肉风味前体物质是指鲜肉中对肉的香气形成起重要作用的非挥发性成分,主要包括水溶性风味前体物质和脂质。本文综述了主要的肉风味前体物质及其与风味品质的关系,为阐释风味品质形成差异的机理提供理论基础。     

不同香型烤烟中各无机元素含量的差异

为了解不同香型烤烟中各无机元素的含量差异,对2011年139个来自我国14个省份不同品种烤烟样品的各无机元素进行了检测,并对检测数据进行了描述统计、方差分析和多重比较分析,结果表明:清香型和浓香型烤烟样品中大部分无机元素指标含量比中间香型烤烟样品的变化幅度要大一些;在大部分无机元素中,省份和品种之间相互作用对它们的影响较大;其中省份效应在钾、锌中影响较大;在各无机元素中,锰、铜、锌的3个指标中3种香型之间存在显著性差异(P0.05)。其中中间香型在铜、锌2个指标上含量显著较高。     

UV-C light inactivation kinetics of Penicillium expansum on pear surfaces: Influence on physicochemical and sensory quality during storage

UV-C inactivation kinetic data of Penicillium expansum on intact and wounded pear disks were determined. P. expansum conidia (0.5 mL, 1.6 × 10⁷ CFU/mL) were spot inoculated onto intact and wounded pear tissue with skin (excised disks), treated with UV-C doses ranging 0.101–3.06 kJ/m² at 23 °C and surviving conidia were enumerated. Changes in selected physicochemical parameters and sensory quality following UV-C treatment of whole pears were determined immediately after treatment, and 4 and 8 weeks of storage at 4 °C. A greater UV-C intensity was required for similar inactivation levels of P. expansum populations on wounded pear disks (3.1 kJ/m² for 2.7 log reduction) compared to intact pear disks (1.7 kJ/m² for 2.8 log reduction). No significant difference in % weight loss, or soluble solids content and texture was observed between UV-C treated and untreated pears. However, browning was observed on UV-C treated pear surfaces after 4 and 8 weeks along with changes in flavor and texture. An increase in consumer preference was noticed for the untreated control pears after 4 weeks storage.     

Effects of carboxymethyl cellulose and chitosan bilayer edible coating on postharvest quality of citrus fruit

There is increasing public interest in development of edible natural biodegradable coatings to replace the currently used commercial synthetic waxes for maintaining postharvest quality of citrus fruit. We tested the efficacy of a newly developed polysaccharide-based edible bilayer coating comprising carboxymethyl cellulose (CMC) and chitosan in preserving postharvest quality of various citrus fruit, including ‘Or’ and ‘Mor’ mandarins, ‘Navel’ oranges, and ‘Star Ruby’ grapefruit after simulated storage and marketing. In all citrus species, it was found that the CMC/chitosan bilayer coating was equally effective as the commercial polyethylene wax in enhancing fruit gloss. Furthermore, the CMC/chitosan bilayer coating slightly increased fruit firmness, especially of oranges and grapefruit, but was mostly not effective in preventing post-storage weight loss. Both the CMC/chitosan bilayer coating and the commercial wax had no significant effects on juice total soluble solids and acidity levels, and had similar effects on gas permeability, as indicated by only slight increases in internal CO₂ levels and in juice ethanol accumulation after storage. Sensory analyses revealed that neither the CMC/chitosan bilayer coating nor the commercial wax coating had any deleterious effects on flavor preference of ‘Navel’ orange and ‘Star Ruby’ grapefruit. However, application of the commercial wax, and moreover the CMC/chitosan bilayer coating, resulted in a gradual decrease in flavor acceptability of ‘Or’ and ‘Mor’ mandarins because of increased perception of off-flavors. Overall, we showed that the CMC/chitosan bilayer edible coating sufficiently enhanced fruit gloss, but was not effective in preventing postharvest weight loss. Furthermore, flavor quality was slightly impaired in mandarins but not in oranges and grapefruit.     

风味型雪莲果饮料的工艺研究

[目的]研究风味型雪莲果饮料的工艺,为进一步加强雪莲果的深加工提供参考。[方法]以新鲜雪莲果为原料进行饮料加工,针对雪莲果在加工过程中出现的褐变、饮料的稳定性、饮料的风味进行了研究。[结果]采用打浆前加入0.20%的NaCl和0.10%的VC于90～95℃的热水中热烫3 min进行护色处理,效果最佳。通过正交试验选择产品配方中明胶为0.18%,CMC-Na 0.10%,琼脂0.12%,雪莲果汁25.00%的处理,产品的稳定性最好。最后通过正交试验确定了风味型雪莲果饮料的最佳配方：白砂糖3.00 g,柠檬酸0.08 g,蜂蜜2.00 ml,雪莲果汁50.00 ml。[结论]试验表明,在此工艺条件下生产出来的雪莲果饮料风味最佳。     

禽肉风味的影响因素

综述影响禽肉风味的各种因素 ,主要包括品种、性别、日龄、日粮、生产制度与环境、屠宰与宰后因素、烹调方式等     

不同氮素水平下喷施顶端调节剂对延边烤烟香气质量的影响

以吉烟9号为试材,研究了不同氮素用量和顶端调节剂互作对烤烟中性香气成分含量及烤后烟叶评吸质量的影响。结果表明:其中高氮、中氮处理满足了烤烟田间生长的肥料需求,顶端调节剂可能提高了烟株的生理活性,不同氮素用量对烟叶中性香气成分含量的影响不同,以T8(中氮+调节剂B)处理中性香气成分含量最高,评吸香气质较好,香气量充足,评吸位居第一。因此,合理施肥和适当的调节措施可提高烤烟香气质量。     

核桃乳饮料生产工艺研究

本文对影响核桃饮料生产的几个主要问题进行了研究。结果表明：核桃仁用３％的ＮａＯＨ溶液去皮后,在０．５％的ＮａＣｌ和０．０２％的Ｎａ２ＳＯ３溶液中护色漂白４ｈ,用８５℃以上热磨的方法可明显改善饮料的色泽和风味。用ＨＬＢ值在１１－１２范围内的复合乳化稳定剂和硬度低于４度的软水在４０ＭＰａ压力下高压均质２次物料,可得到组织状态稳定的核桃乳饮料。     

桃果实品质形成成分与其风味之间的相关性(英文)

测定了白凤桃(PrunuspersicaBatschcv.Hakuho)果实中果汁的糖、酸、氨基酸、挥发性香气成分以及与其相对应的甜味、酸味、香气等风味特性之间的相关关系。结果表明:甜味与可溶性固形物含量呈较高的正相关;酸味与滴定酸呈高的正相关,而与挥发性香气物质十内酯、八内酯、己内酯、可溶性固形物含量呈较高的负相关;3种内酯物质与具有桃芳香风味的特性呈正相关,而与具青气风味特性呈负相关。以风味评定(综合评定)为因变量Y,各种测定成分为主变量X,逐步回归法分析的结果表明,影响桃风味的成分有可溶性固形物含量、滴定酸、十内酯、八内酯、反式-2-己烯醛。其中以酸度和十内酯物质含量的影响为最大。