优化橡木桶陈酿工艺在干红葡萄酒生产中的应用

通过研究陈酿过程中橡木桶陈酿酒所占比例、烘烤程度及陈酿时间三种不同因子对葡萄酒品质的影响,找出其不同水平组合对葡萄酒品质影响的重要性,确定葡萄酒品质最好的水平组合,作为干红葡萄酒的最适陈酿方案。     

Effects of dry aging of bone-in and boneless strip loins using two aging processes for two aging times

This experiment investigated the combined effects of two dry-aging methods (unpackaged and in a bag), two loin-cut styles (bone-in shell loins and boneless strip loins), and two aging times (21 and 28 days) on the physical, chemical, sensory, and microbial properties of dry-aged beef. Sections from shell and strip loin were assigned randomly to be aged unpackaged or aged packaged in a bag with high moisture permeability. Weight losses increased with aging time. Shell loins lost more (P < 0.05) weight during aging compared with strip loins; dry aging in a bag had less (P < 0.05) weight loss than unpackaged aging. There were no differences (P > 0.05) in any of the sensory traits between shell and strip loins or dry aging using a traditional method or in a bag. Dry aging in a bag creates positive effects on yields, no negative effects on product quality, and adds flexibility and control of the aging environment.     

Effects of dry aging of bone-in and boneless strip loins using two aging processes for two aging times

This experiment investigated the combined effects of two dry-aging methods (unpackaged and in a bag), two loin-cut styles (bone-in shell loins and boneless strip loins), and two aging times (21 and 28 days) on the physical, chemical, sensory, and microbial properties of dry-aged beef. Sections from shell and strip loin were assigned randomly to be aged unpackaged or aged packaged in a bag with high moisture permeability. Weight losses increased with aging time. Shell loins lost more (P < 0.05) weight during aging compared with strip loins; dry aging in a bag had less (P < 0.05) weight loss than unpackaged aging. There were no differences (P > 0.05) in any of the sensory traits between shell and strip loins or dry aging using a traditional method or in a bag. Dry aging in a bag creates positive effects on yields, no negative effects on product quality, and adds flexibility and control of the aging environment.     

Connective tissue and aging

Human skin is composed of epidermal and dermal layers, each of which has its own functional importance. Dermis consist of a fine network of collagen fibers, elastic fibers, and other components of the extracellular matrix (ECM). ECM consist primarily of proteins and complex sugars, which form fibrillar networks and a ground substance. Collagen is an important structural component of skin connective tissue and provides the tensile strength of skin. Approximately 70–80% of the dry weight of skin consists of collagen. The most abundant collagen types in skin are types I and III; the former accounts for 80% of the total collagen content of skin and the latter for approximately 15%. The other collagen types present in skin include type IV collagen, which is abundant in the basement membrane (BM); type V collagen, which is located pericellularly; type VI collagen, which plays a role in matrix assembly and is present as microfibrils between collagen fibers; and type VII collagen, which is a structural component of anchoring fibrils. Elastin accounts for only about 1–2% of the dry weight of skin but is important for the maintenance of skin elasticity and resilience. Glycosaminoglycans are of central importance for the maintenance of a water balance in skin, even though the quantities in ECM are small (0.1–0.3% of the dry weight of skin). In the dermis fibroblasts are responsible for the synthesis of ECM proteins. The fibroblasts in the dermis spend majority of time in quiescent state. However in response to activation, the fibroblasts can be reactivated, and certain pool of cell is able to differentiate into myofibroblasts which have important role in repairing skin defects such as during wound healing. During aging the number of fibroblasts is markedly reduced. Also the response of fibroblasts to various growth factors and mechanical or pathological stimulates (wound healing) is diminished. Skin collagen synthesis declines with aging and as the result of such external factors as long‐term sun exposure and medications, for example, topical corticosteroids. In aging skin, collagen fibers become thicker and less soluble and the synthesis of collagen declines. Skin thickness remains quite constant between 20 and 70 years of age, after which a marked decrease in skin thickness occurs. During aging the expression of collagenases are increased and inhibitors of collagenases are reduced leading to increased proteolysis of connective tissue. Recent studies have shown that collagen synthesis is declined in the skin of heavy smokers, while collagenases are increased inducing premature skin aging. The elastic properties of skin are also affected by aging. Along with increasing age, dermal elastic fibers become thicker and fragmented and oxytalan fibers appear fragmented and shortened. Disintegration of elastic fibers is already seen in a minority of fibers between ages 30 and 70, but the changes become more profound after the age of 70 years, affecting a majority of the fibers. As a result of the decreased number of elastic fibers in aged skin, the elastic recovery of skin decreases in elderly people. Even though the content of GAGs and proteoglycans is relatively small, they have significant role in collagen fibril formation, water content of dermis and in mechanical properties. During aging there are marked alterations in different proteoglycans. The amount and synthesis of versican (high molecular size) is decreased and small molecular size decorin is increased. In photoaged skin versican is increased and is closely associated to elastin while decorin is decreased.     

小麦新陈的鉴别

比较小麦新陈鉴别的几种方法。用高锰酸钾滴定法测定过氧化氢酶活动度,可以定量对小麦的新陈进行较准确鉴别。探讨影响此方法的诸多因素以及在测定中对pH值、时间、温度等影响因素的控制条件,力求得到准确的测定结果。     

食醋的人工催陈研究技术

食醋陈酿有自然陈酿和人工催陈方法,都能促进食醋的老熟。自然陈酿食醋老熟慢,但食醋的风味好。人工催陈法有高压静电场、红外技术、超声波技术、微波技术、加臭氧法、激光技术和超高压技术等方法。文章综述了高压静电场、红外、超声波、微波、加臭氧法、激光和超高压对食醋催陈的机理和研究现状。采用人工催陈法提高食醋老熟,可使食醋更接近自然陈酿酒的风味,缩短食醋陈酿的时间。     

两种光老化设备QUV紫外荧光老化试验箱和Q-Sun氙灯老化试验箱比较

紫外荧光老化试验箱QUV采用荧光紫外灯为光源,通过模拟自然阳光中的紫外辐射和冷凝,对材料进行加速耐候性试验,以获得材料耐候性的结果。氙灯老化试验箱Q-Sun采用能模拟全阳光光谱的氙弧灯来再现不同环境下存在的破坏性光波,用来进行老化的环境模拟和加速试验。QUV和Q-Sun同属加速老化和测试材料光稳定性的设备,能提供快速且可重复的测试结果。本文论述了这两种仪器的特点和相关主要标准,并比较了两者之间差别。     

食醋后熟陈酿技术研究

醋酸发酵结束后,醋醅或醋醪经后熟陈酿,可改进食醋的口感、风味.在液态发酵醋醪中利用曲霉酶系反应,可在短时间内增加液态发酵醋的色泽、氨基酸类、糖类、不挥发酸等物质的含量,使口感柔和、增加风味.其特点是:充分发挥曲霉酶系的作用,利用制剂中增加的有效成分,在醋醪中分解与合成,弥补了其风味的不足,从而达到增加和改善液态发酵食醋的目的.方法简便、成本低,是弥补液态发酵食醋风味不足的好办法.     

奶香香精陈化过程中一些化学现象初探

用气相色谱-质谱联用方法对一款自制奶香精新配制时与陈化三月后的成分进行了分析比较,发现并初步解析了其中的几种香原料如酮类、酸类、醛类、内酯类等在陈化过程中发生的一系列化学变化。     

白酒老熟研究进展

该文主要从白酒老熟内在机理和外在因素之间的联系论述了新酒在贮存过程中物质的变化,并分析了影响老熟过程中缔合、酯化、氧化等物质变化的因素以及这些变化之间的相互作用。总结了白酒老熟机理的相关研究以及关于氢键的分子模拟研究,论述了运用分子模拟技术探究老熟深层机理的可行性,为白酒老熟的研究应用提供新思路。阐述了不同温度对白酒老熟过程的影响,主要分析了陶瓷容器和不锈钢容器的不同特性,对比了不同形状、不同环境的贮酒容器的效果。介于白酒老熟过程的复杂程度,将各个因素关联进行多元研究,旨在为白酒老熟相关研究提供新思路以及研究方法参考,推动白酒老熟机理深层次研究。     

酱香型白酒陈酿研究进展

酱香型白酒的陈酿阶段对于提高酒体品质起到至关重要的作用,该文总结了酱香型白酒陈酿机理,陈酿过程中风味物质的变化,贮存条件对酱香型白酒陈酿的影响及人工催陈技术,并对酱香型白酒的陈酿研究前景提出展望,旨在为酱香型白酒的贮存及催陈技术提供理论参考,推动酱香型白酒的陈酿研究。     

Composition of Ragusano cheese during aging

Ragusano cheese is a brine-salted pasta filata cheese. Composition changes during 12 mo of aging were determined. Historically, Ragusano cheese has been aged in caves at 14 to 16 degrees C with about 80 to 90% relative humidity. Cheeses (n = 132) included in our study of block-to-block variation were produced by 20 farmhouse cheese makers in the Hyblean plain region of the Province of Ragusa in Sicily. Mean initial cheese block weight was about 14 kg. The freshly formed blocks of cheese before brine salting contained about 45.35% moisture, 25.3% protein, and 25.4% fat, with a pH of 5.25. As result of the brining and aging process, a natural rind forms. After 12 mo of aging, the cheese contained about 33.6% moisture, 29.2% protein, 30.0% fat, and 4.4% salt with a pH of 5.54, but block-to-block variation was large. Both soluble nitrogen content and free fatty acid (FFA) content increased with age. The pH 4.6 acetate buffer and 12% TCA-soluble nitrogen as a percentage of total nitrogen were 16 and 10.7%, respectively, whereas the FFA content was about 643 mg/100 g of cheese at 180 d. Five blocks of cheese were selected at 180 d for a study of variation within block. Composition variation within block was large; the center had higher moisture and lower salt in moisture content than did the outside. Composition variation within blocks favored more proteolysis and softer texture in the center.     

加速白兰地陈化的研究

研究了在白兰地中加入天然陈化剂的陈化效果。在白兰地中加入经过不同处理、不同品种、不同量的天然陈化剂,在变温条件下进行陈化实验,并利用分光光度计测其吸光度、气相色谱测定乙酸乙酯等色谱骨架成分。结果表明:在变温储藏条件下,经过2%NaHCO3处理的中国橡木CH,添加量为2%时,陈化白兰地的效果较好。     

蚕丝织物上茜草染料的光老化

模拟茜草染色丝绸文物在展览时的自然光老化过程,设计了一套系统的光老化实验.采用荧光紫外灯、卤素灯和白光LED灯,对自制茜草染色样品进行光老化实验,得到3种照明条件下染料的褪色规律曲线,并用高效液相色谱对光老化的内在规律和机制进行更进一步的分析.结果表明:紫外辐射对茜草染料破坏较严重;卤素灯照明下染料褪色速率稍慢于LED...     

含活酵母菌啤酒在储存过程中的变化研究

研究了含活酵母菌啤酒在38℃储存过程中的反-2-壬烯醛、DPPH(1,1-二苯基苦基苯肼)、还原力、总多酚、酵母菌活性和啤酒浊度的变化情况.与不含活酵母菌的啤酒相比较,反-2-壬烯醛的含量有所下降;而DPPH和还原力则没有明显的改善;含活酵母菌啤酒的浊度随酵母菌浓度的增加而提高,随着酵母菌的沉降而有所降低,但活酵母菌浓度较低的啤酒样品的浊度与不含活酵母菌啤酒的浊度相近,且较稳定.     

Physical aging of processed fragmented biopolymers

Low moistures foods containing starches exhibit a sub-T_g endotherm (55–60 °C) when they are stored at constant temperatures. Although the origin of the endotherm is still debatable, it has been attributed to the water–hydroxyl group interactions and/or enthalpic associations between water and carbohydrates. In the present study, physical aging of the starch components of corn flakes prepared with two different levels of starch fragmentation was studied using thermal and rheological methods. A sub-T_g endotherm was observed at temperatures around 50–60 °C by both DSC and Oscillatory Squeezing Flow measurements. An increase of 1.5% of moisture content was observed for both fragmented flakes during aging. The temperatures at which the sub-T_g endotherms occurred were independent of aging and moisture content increase during storage, whilst enthalpy increased with both aging time and moisture content. Although the moisture content of the two types of flakes were different the aging time at which the first endotherm appeared and the rate at which the enthalpy increased were dependent only on the level of starch fragmentation. Corn flakes with a high level of starch fragmentation required a longer period of aging time before the presence of the endotherm could be detected and had a greater rate of increase in enthalpy. Overall, flakes having higher starch fragmentation absorbed more water, and the percent of water uptake decreased with aging time. Flakes with low starch fragmentation exhibited little to no change in water uptake during aging.     

白酒陈酿技术的研究进展

介绍了白酒贮存老熟的机理以及加速白酒贮存老熟的意义.白酒陈酿已引起越来越广泛的兴趣,为梳理白酒陈酿技术的现状和预测未来的发展方向,阐述了当前白酒人工老熟的几种常见方法,分析了这些方法的一些不足之处,并对以后的白酒人工老熟方法的研究提出了建议.