干腌火腿的风味研究

本文综述了意大利Purma,法国Bayonne,西班牙Serran,Iberian干腌火腿的风味感官特征,挥发性和非挥发性芳香风味因素及其研究分析方法,滋味物质及其工艺因素以及挥发性成分与感官分析之间的相关性,旨在为我国金华火腿等的干腌火腿风味机理和工艺现代化研究提供一些理论参考与方法指导。     

Sensory Analysis of Whole Wheat/Soy Flour Breads

ABSTRACT: Breads containing 0% to 40% defatted soy flour, 35% to 100% whole wheat flour, and 0% to 35% white bread flour were prepared. Beany or bitter flavor ratings for the yeast-leavened breads containing up to 30% soy flour were not significantly different from the control whole wheat bread. A high-quality yeast was the most important factor in reducing the beany taste of the bread. Addition of ascorbic acid significantly increased yeasty flavor, and there was a strong inverse correlation between beany and sweet flavors. These studies suggest that an appealing, nutritious bread containing up to 30% to 40% soy flour can be prepared in an easy and economical manner using equipment available in home or institutional kitchens.     

Changes in taste and flavor in aging

This study aims at understanding the role of mixtures (mutual quality suppression) in the evaluation of impact of the human aging process on the perception of taste.

Heretofore, the effect of aging on taste has been directed at threshold and suprathreshold magnitudes of single chemicals (e.g., NaCl, sucrose, citric acid) in aqueous solution. Although absolute thresholds typically rise in advanced age (2 to 9 times, depending on the study), suprathreshold magnitude assessed by magnitude matching seems (except for bitter) to resist change in the way presbycusis spares suprathreshold loudness, fostering the impression that aging may handicap the aged little in the perception of food.

Asked, however, to discriminate the presence‐absence of the prescribed salt flavoring (nominally suprathreshold) in tomato soup, the young outperformed the middle‐aged who, in turn, outperformed the elderly. Moreover, NaCl thresholds in the presence of tomato measured several times higher than in water, but the difference between the young and the elderly continued to hold. Elevation of threshold to much higher levels by mixture suppression leaves the young‐elderly difference unchanged, implying that the elderly may fail to detect salt levels that really count in their diet.

To examine the relation between age and taste mixtures, we measured detection thresholds: (1) for NaCl in citric acid, from zero to strong; (2) for sucrose in citric acid, from zero to strong; and (3) for citric acid in sucrose, from zero to strong. Whether in water alone or in a weak or strong suppressor, the elderly subjects’ threshold was consistently 2 or 3 times higher than that of the young. Moreover, the way in which threshold for one quality rises with concentration of a suppressor is the same, except for constant upward displacement of the elderly peoples’ threshold. In general, both young and elderly confuse salty and sour (show large suppression at all concentrations of the suppressor) much more than they confuse sweet and sour (seen mainly at high concentrations of the suppressor). Study of other mixtures is planned.     

苦苦菜发酵过程中主要发酵菌种及滋味物质的变化

以苦苦菜为原料进行腌制,对自然发酵的苦苦菜进行菌种分离鉴定和总酸度、pH及盐度的测定。游离氨基酸含量用氨基酸自动分析仪分析,并按其味觉强度进行分类。结果表明:苦苦菜发酵初期以植物乳杆菌为优势乳酸菌,呈味氨基酸中苦味氨基酸(Leu、Val、Arg、Ile、Trp、Met)含量较高。主发酵期以植物乳杆菌和短乳杆菌为优势菌群,甜味氨基酸(Ser、Thr、Gly、Ala、His、Pro)和鲜味氨基酸(Glu、Asp、Lys)的含量逐渐增加,而苦味氨基酸含量逐渐降低。发酵后期以发酵乳杆菌为优势乳酸菌,甜味和鲜味氨基酸含量均高于苦味氨基酸。整个发酵过程中芳香族氨基酸(Tyr、Cys、Phe)含量较低且变化不大,发酵中后期7~20d苦苦菜的滋味最好。     

热杀菌条件对酱卤鸭脖品质的影响

为探究不同热杀菌条件对酱卤鸭脖品质的影响,采用氨基酸分析仪、高效液相色谱仪、电子鼻和电子舌等分析3 种热杀菌条件（90 ℃、15 min,90 ℃、30 min和121 ℃、15 min）和未杀菌酱卤鸭脖的品质指标变化。结果表明：随热杀菌温度或时间的增加,酱卤鸭脖中蛋白质、脂肪、硫胺素和氯化钠含量均减少,而高温杀菌（121 ℃、15 min）组含量显著减少（P＜0.05）;感官评价结果显示,高温杀菌减少鸭脖的肉香味并产生异味,鲜味和咸味评分显著降低（P＜0.05）;电子鼻对未杀菌组和90 ℃、15 min组区分能力较弱,对其余处理组均能有效区分;电子舌结合呈味核苷酸和氨基酸分析可知,热杀菌条件对鸭脖的鲜味和咸味影响显著（P＜0.05）,而引起鲜味改变的主要滋味物质是谷氨酸、5’-鸟苷酸和5’-肌苷酸。低温长时杀菌对酱卤鸭脖品质有积极作用,而高温热杀菌对鸭脖品质易产生不良影响。     

Thickening Agents Effects on Sodium Binding and Other Taste Qualities of Soup Systems

Low sodium chicken broth with NaCl added to provide Na⁺ concentrations in typical reduced Na⁺ soups (144 and 288 mg Na⁺/240 mL serving) was thickened with commonly used gum, starch, or flour food additives. Xanthan gum suppressed saltiness as the result of ionic binding of Na⁺, as determined by sensory evaluation and ²³Na NMR spectroscopy. Saltiness was affected by added NaCl (p = 0.0001), thickener (p < 0.01), and added NaCl* thickener (p < 0.01), and positively correlated with chicken and overall flavors (p = 0.0001). Cornstarch provided body, no suppression of salt taste, and the greatest salt enhancement of chicken and overall flavors. In complex food systems, temperature and other factors affected Na⁺ binding as measured by NMR pointing to the need for a new model.     

武定鸡肉中鲜味肽分离鉴定及呈味特性

利用超滤分级、凝胶过滤色谱法和反相-高效液相色谱法对武定鸡肉中鲜味肽进行分离纯化,结合感官评价追踪鲜味最强烈的组分,以纳升高效液相色谱-串联质谱联用技术与固相合成法对鲜味肽进行鉴定和合成,进一步分析鲜味肽的序列来源及其呈味特征。结果表明：从武定鸡肉中分离鉴定出8 条多肽,分子质量范围为365.20～1 735.92 Da,其中LDF、FVT和DLAGRDLTDYLMKIL这3 条肽段具有明显的鲜味活性,阈值在0.062～0.250 mg/mL之间,是武定鸡肉鲜味的关键组分。     

Sugar reduction without compromising sensory perception. An impossible dream?

ABSTRACT

Sugar reduction is a major technical challenge for the food industry to address in response to public health concerns regarding the amount of added sugars in foods. This paper reviews sweet taste perception, sensory methods to evaluate sugar reduction and the merits of different techniques available to reduce sugar content. The use of sugar substitutes (non-nutritive sweeteners, sugar alcohols, and fibres) can achieve the greatest magnitude of sugar and energy reduction, however bitter side tastes and varying temporal sweet profiles are common issues. The use of multisensory integration principles (particularly aroma) can be an effective approach to reduce sugar content, however the magnitude of sugar reduction is small. Innovation in food structure (modifying the sucrose distribution, serum release and fracture mechanics) offers a new way to reduce sugar without significant changes in food composition, however may be difficult to implement in food produced on a large scale. Gradual sugar reduction presents difficulties for food companies from a sales perspective if acceptability is compromised. Ultimately, a holistic approach where food manufacturers integrate a range of these techniques is likely to provide the best progress. However, substantial reduction of sugar in processed foods without compromising sensory properties may be an impossible dream.     

早籼配制米配方及加工技术

为改善低质早籼米品质,在分析浙江省主栽早籼基米米质基础上采用籼米之间配制技术。配方研究是以控制直链淀粉含量为核心,以长宽比相近为原则,通过调整不同直链淀粉含量品种的搭配比例,达到直链淀粉含量15%~20%且改善其早籼米饭过硬或过粘的食味特性的目的。对配方米的米质和食味的鉴定结果表明配制米米质和食味品质明显好于单一早籼基米。在配米生产工艺上采用原料搭配或成品搭配,使配米精度优于1%,混合均匀度变异系数CV≤10%。