赖氨酸Amadori和Heyns化合物热裂解产物对烟草风味的影响研究

  目的  比较赖氨酸Amadori和Heyns化合物的热解产物及对其烟草风味的影响。  方法  以赖氨酸和葡萄糖或果糖为原料,以偏重亚硫酸钠为催化剂、甲醇和冰醋酸为溶剂,分别合成赖氨酸的Amadori和Heyns化合物,采用在线热裂解-气相色谱/质谱联用技术(Py-GC/MS)对比了2种化合物的热解产物差异,并通过感官评吸实验比较了二者对卷烟风味的影响。  结果  （1）赖氨酸Amadori和Heyns化合物热解均能产生醛酮类、呋喃类、吡啶类、吡嗪类及吡咯类香味物质,同一类别产物的相对含量有较大差异。（2）赖氨酸Heyns化合物热解得到的风味成分数量更多。（3）赖氨酸Amadori化合物和Heyns化合物对卷烟的主要作用为增香、增浓和降低刺激,并使烟气更加流畅顺滑,赖氨酸Heyns化合物增加了卷烟白肋烟特征。  结论  赖氨酸Amadori化合物和Heyns化合物的热解产物不同,对卷烟风味的影响存在差异。      

美拉德反应中间体对卷烟评吸品质的影响及其风味受控形成研究

完全美拉德反应产物(MRPs)是构成烟草特征香味的重要来源,但普遍存在易逸失、不稳定的问题。以果糖为原料,制备了6种Heyns重排产物(HRP)类美拉德反应中间体,通过卷烟感官评吸筛选发现,果糖和苯丙氨酸反应得到的中间体2-脱氧-2-L-苯丙氨酸-D-葡萄糖具有最理想的加香效果。比较了苯丙氨酸—果糖的完全美拉德反应产物溶液和相应中间体HRP溶液的后续热加工稳定性,随着热处理时间延长,完全美拉德反应产物的香气降低了74.7%,而中间体HRP溶液挥发性风味成分增加为未加热的12.1倍,具有加工风味受控形成的特点,从而很好地克服了完全美拉德反应产物在食品、烟草加工过程中的加香缺陷。     

不同品种和加工工艺制得黑蒜的成分分析

目的比较不同品种和加工工艺制得黑蒜的成分。方法以独头蒜和多瓣蒜为试验材料,采用湿热加工法制备黑蒜,与相应鲜蒜和干热加工法生产的黑蒜(市售)比较,分析其主要成分的变化。采用苯酚硫酸法测定总糖含量,福林酚法测定多酚样物质含量,DPPH、ABTS、超氧阴离子自由基清除率以及FRAP法测定抗氧化性,硫酸钡吸光比浊法测定总硫含量,高效液相法测定含硫化合物含量。结果独头蒜与多瓣蒜相比,其总糖含量较高,但多酚样物质含量无明显差异;其DPPH自由基清除率较低,但ABTS和超氧阴离子自由基清除率以及总抗氧化能力无明显差异;除蒜氨酸含量稍高外,总硫、二烯丙基二硫(diallyl disulfide,DADS)和二烯丙基三硫(diallyltrisulfide,DATS)含量均无明显差异。无论独头蒜还是多瓣蒜,湿热加工成黑蒜后,总糖含量和多酚样物质均含量增高;ABTS、DPPH、超氧阴离子自由基清除率和总抗氧化能力均显著增高;蒜氨酸、DADS和DATS含量均降低,但S-烯丙基半胱氨酸(S-allyl cysteine,S-AC)含量增高,总硫含量无明显变化。湿热加工法制备的黑蒜与市售黑蒜相比,湿法加工黑蒜其多酚样物质含量较高,而市售黑蒜总糖含量较高;其ABTS、DPPH、超氧阴离子自由基清除率和总抗氧化能力均较高;蒜氨酸、DADS和DATS含量均较高,而S-AC含量较低。结论独头蒜与多瓣蒜制备而得的黑蒜的主要成分无明显差异。湿热加工法制备的黑蒜与市售黑蒜相比,抗氧化性较强,但S-AC含量较低。不同大蒜品种和加工工艺制备黑蒜可以为黑蒜生产和功能特性探究提供依据。     

Changes in antioxidant activity of dehydrated onion and garlic during storage

The effect of the Maillard reaction evolution on the overall antioxidant activity (AA) of stored dehydrated onion and garlic has been studied. Extent of the reaction was followed through the determination of the Amadori compounds, measured as 2-furoylmethyl-amino acids (2-FM-AA), and colour development whereas AA was evaluated by the ORAC_FL assay. Dehydrated garlic exhibited a very slow progress of the Maillard reaction which did not lead to any noticeable change in its AA upon storage. However, a substantial increase of AA was observed in dehydrated onion samples, in agreement with a major Maillard reaction evolution. Moreover, a positive correlation between colour and antioxidant properties was observed during the storage of dehydrated onion at 50 °C, suggesting the predominant role of the advanced stages of the Maillard reaction over the AA. In conclusion, this study demonstrated that, although the Amadori compounds might exert a moderate effect on the AA, the advanced Maillard reaction products are the major contributors to this property.     

Bioactive compounds,in vitro antioxidant capacity and Maillard reaction products of raw,boiled and fried garlic (Allium sativum L.)

Garlic is used in many dishes but some of its bioactive compounds are lost when exposed to heat. This study evaluated bioactive compounds, antioxidant activity and Maillard reaction products of raw (RG), boiled (BG) and fried garlic (FG). Total phenolic compounds, flavonoids, allicin and phytosterol were quantified as well as dietary fibres and mineral content. Antioxidant activities of RG, BG and FG were evaluated by oxygen radical absorbance capacity (ORAC), oxidation of β‐carotene/linoleic acid and Rancimat methods. The main results were the following: thermal processing of RG decreased both bioactive compounds and antioxidant capacity, boiling was found to be less aggressive than frying, and strong correlations were obtained between total phenolic compounds and the antioxidant assays. However, phytosterol content was higher in FG than in RG and BG and higher temperatures increased the formation of Maillard reaction products. It was concluded that RG and BG should be preferred for human consumption as they present higher antioxidant capacity.     

Comparison of Immunomodulatory Effects of Fresh Garlic and Black Garlic Polysaccharides on RAW 264.7 Macrophages

Garlic has a long history to be used for medicine and food purposes. Black garlic, the fermented product of fresh garlic, is considered with better biological activities, such as antioxidant activity, and is developed as an increasingly popular functional food. Polysaccharides are the major components of fresh and black garlic, and immunomodulatory activity is one major pharmacological effect of polysaccharides. Therefore, chemical characteristics and immunomodulatory effects of polysaccharides from fresh and black garlic are investigated and compared in vitro for the 1st time, in order to reveal their molecular and pharmacological differences. It is demonstrated that the molecular weights of polysaccharides from the 2 sources and molar ratios of monosaccharides after acid hydrolysis are greatly variant. The effects of polysaccharides from 2 sources on RAW 264.7 macrophages functions, including promotion of phagocytosis, release of NO, and expressions of several immune‐related cytokines (including interleukin [IL]‐6, IL‐10, tumor necrosis factor alpha, and interferon gamma), were different from each other. The results indicated that fresh garlic polysaccharide exhibited stronger immunomodulatory activities than that of black garlic. Moreover, it is revealed that fructan might be the bioactive component in garlic and it is indicated that during the fermentation treatment, fructan constituents of garlic has degraded, and basically no immunomodulatory effect can be found in black garlic polysaccharides.     

黑蒜提取物的抗氧化性与抗炎活性比较研究

目的对分离纯化黑蒜多糖的过程中得到6种黑蒜提取物,进行成分分析,并比较研究它们的抗氧化活性和抗炎活性。方法黑蒜经热水提取获得黑蒜水提物(hot water extract,HWE),经乙醇分离得到乙醇上清(ethanol supernatant extract,ESE)和沉淀(ethanol precipitate extract,EPE)提取物,并再经脱蛋白和乙醇分离得到脱蛋白的乙醇上清(deproteinized ethanol supernatant extract,d ESE)和沉淀(deproteinized ethanol precipitate extract,d EPE)提取物,再经DEAE 52纤维素层析纯化得到多糖提取物(purified polysaccharide extract,PPE)。首先采用薄层层析法分析了6种黑蒜提取物的单糖组成,还测定了总糖含量、还原糖含量、硫含量。再比较分析了6种多糖提取物的抗氧化与抗炎活性。结果 6种黑蒜提取物对DPPH自由基和ABTS自由基均具有良好的清除作用。6种黑蒜提取物对脂多糖(lipopoly saccharides,LPS)(20?g/mL)所致的RAW264.7细胞生长抑制均有显著性保护作用(P0.05)。6种黑蒜提取物对LPS(1?g/mL)诱导RAW264.7细胞NO,IL-1?,IL-6和TNF-?等细胞炎性因子的释放均有显著的抑制作用(P0.05)。结论黑蒜多糖提取物具有良好的抗氧化作用和抗炎活性,研究结果为黑蒜的进一步研发提供了理论依据和实际参考价值。     

黑蒜中5-羟甲基糠醛的生成规律及安全性评价

黑蒜在加工过程中进行糖类热降解反应和美拉德反应会生成一定量的5-羟甲基糠醛(5-hydroxymethylfurfural,5-HMF),其既具有毒理性又具有药理性,研究该物质的生成规律和安全性可以对黑蒜的食用安全性提供重要依据.本研究通过测定黑蒜加工过程中5-HMF和还原糖、总酸以及总游离氨基酸的含量变化并分析其相关...     

黑蒜加工过程中主要营养物质及抗氧化活性变化的研究

目的探究大蒜在发酵成为黑蒜过程中主要营养物质及抗氧化活性的变化。方法将新鲜大蒜置于高温密闭环境中发酵,定期测定蒜样的水分、还原糖、总酸、蛋白质及总酚的含量和抗氧化活性。结果在高温高湿条件下,随着发酵时间的延长,蒜瓣水分逐渐丧失,还原糖、总酸、蛋白质、总酚含量相对提高, 25 d时黑蒜的还原糖含量较鲜蒜增加12.19%,总酚含量提高6.7倍,蛋白质含量增加3.14 mg/g DW;抗氧化性能总体增加, DPPH清除能力提升了2.6倍。结论适宜的条件下发酵形成的黑蒜具有更高的营养价值和抗氧化活性。     

Formation,nutritional value,and enhancement of characteristic components in black garlic: A review for maximizing the goodness to humans

Black garlic (BG) is essentially a processed food and obtained through the transformation of fresh garlic (FG) (Allium sativum L.) via a range of chemical reactions (including the Maillard reaction) and microbial fermentation. This review provides the up‐to‐date knowledge of the dynamic and complicated changes in major components during the conversion of FG to BG, including moisture, lipids, carbohydrates (such as sugars), proteins, organic acids, organic sulfur compounds, alkaloids, polyphenols, melanoidins, 5‐hydroxymethylfurfural, vitamins, minerals, enzymes, and garlic endophytes. The obtained evidence confirms that BG has several advantages over FG in certain product attributes and biological properties (especially antioxidant activity), and the factors affecting the quality of BG include the type and characteristics of FG and processing technologies and methods (especially pretreatments, and processing temperature and humidity). The interactions among garlic components, and between garlic nutrients and microbes, as well as the interplay between pretreatment and main manufacturing process, all determine the sensory and nutritional qualities of BG. Before BG is marketed as a novel snack or functional food, more research is required to fill the knowledge gaps related to quantitative monitoring of the changes in metabolites (especially those taste‐active and/or biological‐active substances) during BG manufacturing to maximize BG's antioxidant, anticancer, antiobesity, anti‐inflammatory, immunostimulatory, anti‐allergic, hepatoprotective, cardioprotective and oxidative stress‐/hangover syndrome‐reducing functions, and beneficial effects on memory/nervous systems. Assessments of the quality, efficacy, and safety of BG should be performed considering the impacts of BG production conditions, postproduction handling, and intake methods.     

造纸法再造烟叶氨基酸、Amadori化合物含量分析及工艺影响研究

氨基酸、Amadori化合物与造纸法再造烟叶感官品质密切相关,本文研究国内外代表性造纸法再造烟叶产品中氨基酸、Amadori化合物含量差异,并结合再造烟叶生产过程中氨基酸、Amadori化合物含量变化趋势分析,以指导国产造纸法再造烟叶工业控制.研究结果表明,国内外造纸法再造烟叶产品中氨基酸、Amadori化合物含量有较...     

Amadori化合物合成方法综述

综述了国内外3类主要的合成Amadori化合物的方法:保护和非保护葡萄糖合成法,以及保护果糖合成法,并将这些方法进行了对比,认为热稳定性较差的、与葡萄糖直接反应活性低而又需要较高分离产率的氨基酸可采用保护果糖的方法来制备Amadori化合物。     

Physicochemical Properties and Antioxidant Capacity of Chinese Olive (Canarium album L.) Cultivars

In this study, the physicochemical characteristics and antioxidant potentials of 10 Chinese olive cultivars were investigated. Considerable differences were found between cultivars in weight, edible yield, water content, size, shape, total soluble solids, and total titratable acidity. The major sugars and organic acids in all the cultivars were glucose, fructose, and malic acid. Phenolics were the most abundant antioxidants (1174.0 to 1799.6 mg gallic acid equivalents/100 g fresh weight). Twelve phenolic compounds were identified and quantified by UPLC‐MS/MS. Six compounds were identified first in the Chinese olive, with 3‐O‐galloylquinic acid and geraniin isomers as the most abundant compounds. The results also indicated that the phenolic content (TPC) correlated with the antioxidant properties of Chinese olive fruit extracts. A principal component analysis indicated that the Tantou and Tanxiang cultivars were a valuable source, with high TPC and antioxidant activity, whereas Maken22, Changying, and Green changying cultivars may be eaten fresh and had high sugar and low phenolic contents. This information will be useful for selecting suitable cultivars for industry and the market.     

Study of texture properties of ‘laba’ garlic in different color states and their change mechanisms

In addition to color, texture of ‘laba’ garlic can also change. To study texture properties of ‘laba’ garlic and their change mechanisms during pickling, texture, ultrastructures, membrane permeability, water status, wall polysaccharides contents, and enzyme activities of garlics in three color states (white, green, and yellow) were studied. The results showed that the firmness, fracturability, membrane permeability, malonaldehyde, protopectin, and chelator-soluble pectin contents, and cellulase and polygalacturonase activities of garlic decreased significantly (P < 0.05), while the water, cellulose, and water-soluble pectin contents, and pectin methylesterase (PME) activity increased after pickling. In addition, the more content of free water and less content of immobilised water were contained in ‘laba’ garlic than in fresh garlic owing to wall degradation and water translocation, especially in yellow garlic. In summary, texture changes in ‘laba’ garlic are mainly dependent on pectin composition, water status, and PME activity.     

Influence of Steeping Solution and Storage Temperature on the Color Change of Garlic

ABSTRACT:  The objective of this study was to investigate the browning of garlic under different steeping conditions and storage temperatures. The brown indices of steeped garlics showed lowest values (7.3 and 7) in 25% and 50% EtOH at 7 d of storage. The degree of browning of steeped garlics was lowest (10.2 in 25% EtOH and 10.4 in 50% EtOH) in the samples soaked for 8 h at 13 d of storage. As the storage temperature was increased from 10 to 40 °C, the brown indices of garlics revealed an increasing trend relative to storage time regardless of steeping treatment. Overall, the kinetic parameters showed relatively low  R ² and irregular reaction constants, but the  k_o  values showed an increasing trend with temperature under a zero-order model. The highest polyphenol content within the garlic bulbs was seen in controls (without steeping treatment, 588.9 μg/g), than 0% EtOH (water, 392.5 μg/g), than 25% EtOH (211.3 μg/g), and finally 50% EtOH (155.6 μg/g). The polyphenol oxidase activity of garlic showed a similar trend to that of polyphenol content. However, the texture properties of garlics steeped with 25% and 50% did not change.
Practical Application: The garlic color preferred by consumers is a creamy-white, but this is susceptible to enzymatic browning when pre-peeled and chopped. When garlic was steeped in the 25% and 50% alcohol, the browning of garlic was prevented during storage.     

人参、大蒜混合发酵过程中微生物多样性、成分及抗氧化能力分析

探究人参与大蒜混合发酵对黑参微生物多样性、成分以及生理功能的影响。以新鲜大蒜和人参为原料,采用液态发酵法自制黑蒜、黑参和参蒜,对其发酵过程中微生物多样性、主要成分以及抗氧化性进行分析。结果表明：参蒜产品的优势菌门为厚壁菌门,优势菌属为uncultured_bacterium_f_Muribaculaceae、乳杆菌属等;根据京都基因与基因组百科全书进行代谢途径预测,参蒜与大蒜和人参的代谢途径无明显差异,主要为全局及概要图、碳水化合物代谢和氨基酸代谢;参蒜的还原糖含量和总酚含量显著提高,总酸含量下降,稀有人参皂苷转化率显著提高,潜在有害物质5-羟甲基糠醛含量显著下降;参蒜具有良好的自由基清除能力。以上研究为参蒜产品的开发、促进黑参产业的发展提供理论依据。     

不同加工工艺对黑蒜产品品质的影响

黑蒜是一种新型大蒜加工制品,通过不同加工工艺得到两种不同的产品黑蒜1号和黑蒜2号,其中黑蒜1号的生产周期为黑蒜2号的3倍。本研究比较了两种加工工艺对黑蒜基本营养成分、蒜氨酸含量以及自由基清除能力的影响。研究表明:与新鲜大蒜相比,黑蒜的水分含量较少约为40%,湿基中的可溶糖、蛋白质和多酚显著增多(P0.01),蒜氨酸含量减少。而干基中的营养物质除多酚外,其余成分都减少,脯氨酸和精氨酸急剧降低,变异系数分别为1.03和1.12。湿基对OH·的清除能力基本一致,对DPPH·的清除力为新鲜蒜的2倍。黑蒜1号的粗蛋白含量低于黑蒜2号,可溶糖、多酚、蒜氨酸皆高于黑蒜2号,粗蛋白和多酚变异系数达到0.20左右,各组分间存在显著差异(P0.05)。在不同浓度下对自由基清除能力相同,当浓度为0.05 g/m L时,对OH·和DPPH·的清除率达到了90%以上。电子舌可以有效的区别两种产品。     

Changes of Flavor Compounds of Hydrolyzed Chicken Bone Extracts during Maillard Reaction

Flavor quality, including non‐volatile and volatile compounds, of hydrolyzed chicken bone extracts (HCBE) during Maillard reaction (MR) was evaluated with HPLC, tasting sensory system, Electronic‐Nose (E‐nose), and GC‐MS. Results showed that flavor amino acids (AA) accounted for 72% to 74% of total free AA in HCBE. Taste of umami increased first and then decreased during MR, while equivalent umami concentration remained at a stable level. Results of taste sensing system and bitter AA showed that MR could reduce the bitter taste of HCBE significantly. E‐Nose test showed there are great changes of volatile flavor during MR. And total of 59 volatile compounds were identified in HCBE during MR, which should responsible for the increase of flavor in HCBE. Our results indicated that MR could be used as an effective way to change the flavor compounds in HCBE, and therefore provide a strategy for preparation of meaty flavor enhancer from bone residue as a byproduct of meat industry.     

Chemistry of Amadori rearrangement products: Analysis,synthesis, kinetics,reactions, and spectroscopic properties

The chemistry of the key intermediate in the Maillard reaction, the Amadori rearrangement product, is reviewed covering the areas of synthesis, chromatographic analyses, chemical and spectroscopic methods of characterization, reactions, and kinetics. Synthetic strategies involving free and protected sugars are described in detail with specific synthetic procedures. GC‐ and HPLC‐based separations of Amadori products are discussed in relation to the type of columns employed and methods of detection. Applications of infrared (IR) and nuclear magnetic resonance (NMR) spectroscopy for structural elucidation of Amadori products are also reviewed. In addition, mass spectrometry of free, protected, and protein‐bound Amadori products under different ionization conditions are presented. The mechanism of acid/base catalyzed thermal degradation reactions of Amadori compounds, as well as their kinetics of formation, are critically evaluated.     

Fructo-oligosaccharide changes during the storage of dehydrated commercial garlic and onion samples

The composition of fructo-oligosaccharides (FOS), together with glucose, fructose and sucrose, has been determined in commercial dehydrated samples of onion ( Allium cepa L.) and garlic ( Allium sativum L.). No qualitative differences were detected among the FOS identified in both onion and garlic. Results show a lower FOS content in garlic than in onion in all samples analysed. In garlic samples, FOS with degree of polymerisation from 3 to 7 were identified and quantified for the first time. In addition, a study on the effect of the storage in these carbohydrates has been carried out under controlled conditions (50 °C, a _w 0.44). The storage seemed to promote important changes in the content of glucose and fructose, which could participate in the Maillard reaction and in the composition of sucrose and FOS, whose hydrolysis was noticeable during the storage time. Therefore, all these chemical changes should be considered to evaluate the quality of these foods.