辣椒制品中大红粉的筛查及检测

采用自制的微型GPC柱对辣椒制品中的非食用色素进行筛查,筛选到一种未知的脂溶性非食用色素,采用紫外可见光谱法、高效液相色谱法、液相色谱-质谱/质谱法及液相色谱-飞行时间质谱法对该未知色素与市售化工染料大红粉进行比较分析,发现该未知色素为大红粉(Pigment Scarlet Powder).为了有效开展食品中大红粉的检测,建立了一种直接溶剂提取法对辣椒制品中大红粉进行检测的方法,该方法操作简便,可实现对辣椒制品中大红粉的快速检测,并在部分辣椒制品中检出大红粉.     

Antioxidative effect of dietary grape pomace concentrate on lipid oxidation of chilled and long-term frozen stored chicken patties

Grape pomace concentrate (GPC) is a natural source of phenolic compounds with high antioxidant capacity. The effect of a diet containing GPC on lipid peroxidation levels (TBARS) and antioxidant capacity (ABTS method) of raw and cooked chicken breast meat patties stored in chilled conditions (4 °C) for 0, 3, 6, 13 and 20 days, and long-term frozen storage (6 months) was investigated. Chickens were fed GPC at levels of 0, 30 and 60 mg/kg from 3 to 6 weeks of age. Dietary GPC did not affect chicken performance. Lipid oxidation (TBARS value) was significantly increased by the storage time (0–20 days and 6 months of storage, respectively) in raw and cooked samples. Dietary GPC significantly caused an inhibitory effect on lipid oxidation of raw and cooked breast chicken patties compared with samples obtained from birds fed the control diet at 20 days and long-term frozen storage (6 months). Radical scavenging capacity was significantly increased at 20 days in cooked samples and significantly reduced at 6 months of storage in raw and cooked samples. The higher concentration of dietary GPC increased the ABTS values only in the raw samples. These results indicated that dietary grape pomace concentrate could be effective in inhibiting lipid oxidation of chilled and long-term frozen stored chicken patties.     

益生菌乳酸发酵提高低聚果糖含量生产的新方法

研究报告了一种新的提高低聚果糖(FOS)含量的生产方法。以市售低聚果糖为原料,通过添加甜菜碱进行益生菌乳酸发酵,将原料中可发酵性糖葡萄糖、果糖转化为乳酸,蔗糖部分转化为乳酸,使原料中低聚果糖的含量由51%提高到84%,而发酵液无需进行菌体分离即可用于食品加工,为低聚果糖的生产提供了一种低成本、高效率的纯化方法。     

Properties of Arrowroot Starch Treated with Aqueous HCl at Ambient Temperature

Arrowroot starch was acid-treated using 2.2 M HCl at 29 to 30° C for durations of 0 to 72 h, and properties of the control and modified samples were compared. Increasing length of acid treatment produced a progressive decline in amylose blue value, intrinsic viscosity, and swelling power, as well as an increase in free sugars and solubility. Differential scanning calorimetry (DSC) studies highlighted changes effected by acid-treatment in the gelatinization behavior of the starch samples. Gel permeation chromatography (GPC) studies on 32- and 72-h acid-treated samples indicated a greater proportion of dextrins with a higher percentage of reducing sugars, compared to the control. While X-ray diffraction data suggested minor changes in the crystal phase impacted by acid-treatment, in vitro digestibility of both control and acid-treated samples did not show any appreciable change in overall patterns.     

发芽糙米营养成分及淀粉糊化特性研究

以3个粳稻和2个糯稻为原料,制备发芽糙米,分析了糙米发芽前后游离氨基酸、蛋白质、水溶性糖类、脂肪酸值以及Mixolab淀粉糊化特性的变化。结果表明,与糙米相比,发芽糙米游离氨基酸总量、水溶性总糖、还原糖及果胶酸含量显著增加。Mixolab混合仪测定的发芽糙米米粉团蛋白质结构严重弱化,淀粉糊化能力显著降低。油酸含量和脂肪酸值均增加。发芽糯糙米水溶性总糖、还原糖及果胶酸含量显著高于发芽粳糙米,破损淀粉含量显著低于发芽粳糙米。     

酸法水解玉米芯制备还原糖液及其在烟用反应型香料中的应用

玉米芯中富含木糖和阿拉伯糖,研究表明玉米芯是生产Maillard反应香料前驱体—戊糖的良好原料。以玉米芯为原料,提取得到戊聚糖,运用稀酸水解法获得还原糖液。HPLC-ELSD法测定表明还原糖液富含木糖和阿拉伯糖。将标准化的还原糖液与氨基酸混和后,经Maillard反应获得了不同风味的反应型香料,为反应型香料的生产找到了一种廉价易得的戊糖原料,并为农产品加工废弃物—玉米芯找到了新的利用途径。     

乙酸木质素改性聚氨酯材料的制备及热力学性能研究

试验采取乙酸制浆法对多枝桉木片进行蒸煮,并提取了蒸煮废液中的木质素.采用红外光谱和凝胶渗透色谱(GPC)分析了乙酸木质素的化学结构和相对分子量分布.用得到的乙酸木质素(AAL)对传统的聚氨酯材料进行了改性,采用TG和DSC热力学实验对改性聚氨酯材料的热力学性质进行了研究.结果表明,添加的乙酸木质素很好地参与了反应,与聚氨酯材料在分子结构尺度上成为了一个整体.同时,木质素的添加可以明显改善聚氨酯材料的热力学性能.     

Generation of Mannitol from Copra Meal

Saccharification of copra meal with hydrochloric acid was found to be suitable method for forming reducing sugars. The presence of protein and lignin in the meal did not have a significant effect on the yield of reducing sugars. Borohydride reduction of the reducing sugars gave sugar alcohols in 44% yield based on the raw material or 81% based on carbohydrate content. The sugar alcohol mixture contained 66% mannitol, 24% sorbitol and 5% galactitol. The recovery of hydrochloric acid which renders the process more economically feasible was done by vacuum distillation.     

Investigating the relationship between the hair fiber proteome and hair quality

Many hair characteristics (e.g. color and curl) are genetically determined. Here, we investigated whether hair quality is also genetically controlled and related to differences in hair composition. Female, Caucasian subjects ( n  = 292) were recruited into this study and segmented by self-perceived hair quality and by permanent colorant usage. Hair fibers were collected and characterized by amino acid analysis, dry tensile elastic modulus testing and two-dimensional electrophoresis of hair protein extracts.
Protein analysis revealed a string of 66 kDa proteins that correlated with hair of high quality. Loss of low molecular weight (14–29 kDa) proteins increased with colorant usage, particularly in hair of low quality. Amino acid analysis showed that the levels of serine and threonine across all the subjects followed bimodal frequency distributions suggestive of a genetic influence. Overall, data suggested that perception of quality was linked to high serine and threonine levels. In addition, where hair was colored, quality was associated with lower cysteic acid levels. Lower cysteic acid levels were not linked to lower colorant usage and our data suggest that high quality hair may be more resistant to colorant damage. Elastic modulus was significantly higher in hair of higher quality (4.65 GPa) compared to all medium and low quality hair combined (4.3 GPa), P  < 0.02. This suggests a link between altered hair composition and mechanical properties. In conclusion, the composition and mechanical properties of hair have been linked to hair quality. We hypothesize that hair quality is thus likely to be genetically determined. Understanding of the links between hair composition and its properties could be utilized in the future for designing products targeted to each individual's hair make-up, and for producing diagnostic tools for determining hair quality.     

PHYSICAL, PHYSIOLOGICAL AND CHEMICAL CHANGES IN POTATO AS INFLUENCED BY ERWINIA CAROTOVORA INFECTION

Bacterial soft rot, caused by Erwinia carotovora ssp. carotovora (Ecc), is a major disease in stored potatoes. The pathogen causes different physical, physiological and chemical changes in potatoes, which may affect the acceptability of raw and processed products. This study was carried out to evaluate the effect of disease severity on different physico-chemical and physiological properties of raw and cooked potatoes and to select the parameters most responsive to disease severity. Potatoes were inoculated with bacteria and incubated at 20C for different lengths of time to produce different levels of disease. As incubation time increased the volume of disease (VDS) increased, which in turn influenced the respiration rate (RR). In both raw and cooked potatoes, the physical changes (texture and color) associated with the progress of disease were reduced hardness, firmness and L value, and increased a and b values and total color difference (ΔE). The chemical changes were reduced ascorbic acid and pH, and increased reducing sugars, total sugars and titrable acidity along with the activities of peroxidase and polyphenol oxidase. The changes in physical and chemical parameters of raw and cooked potatoes during storage were described by fractional conversion equation models. All parameters were quite sensitive to disease except reducing sugars, peroxidase and PPO activity. The correlation matrix indicated that several of the quality parameters were related and thus most of them could be successfully used to predict tuber quality from disease.     

Structural Identification and Antioxidant Properties of Major Anthocyanin Extracted from Omija (Schizandra chinensis) Fruit

ABSTRACT:  Omija ( Schizandra chinensis ) is used as an ingredient in traditional medicine in East Asia. It is consumed as tea and wine and display pinkish-red color and beneficial physiological activity. However, the origin of Omija's unique color and bioactivity has not been studied extensively and its application is very limited. Thus, it was required to determine the chemical structure of major phenolic compounds of Omija fruit and evaluate their antioxidant activity. The colorants extracted from a domestic Omija cultivar were concentrated by a Sep-pak® Plus C₁₈ cartridge. A major high-performance liquid chromatography (HPLC) peak of anthocyan represented 94.1% of total absorbable compounds at 520 nm, which was further identified by LC-ESI-MS. The mass-to-charge ratio ( m/z ) of the major anthocyan was determined to be 727. Highly pure anthocyan fraction with a semipreparative HPLC was acid-hydrolyzed, and the sugar moieties linked to anthocyan (cyanidin) were characterized by thin layer chromatography (TLC) and high-performance anion exchange chromatography (HPAEC) analyses. The linkage patterns of sugars and core cyanidin structure were determined by ¹H- and ¹³C-NMR analyses. Antioxidant activity of the extract and the purified anthocyanin was evaluated by 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) methods. As a result, the structure of the purified colorant was identified as Cya-3- O -xylrut. At the same molar level of the samples tested, the purified Cya-3- O -xylrut (31.2% and 39.2%) had substantially greater antioxidant activity than l -ascorbic acid (17.1% and 10.1%) from DPPH and ABTS methods, respectively. In this study, Omija colorant mostly consisted of Cya-3- O -xylrut explained 86% (DPPH) and 98% (ABTS) of total antioxidant activity derived from water extract from Omija.     

ENERGY REQUIREMENTS OF BEET COLORANT PRODUCTION

Energy requirements were monitored during the production of a beet colorant on a pilot plant scale. Colorant production involved centrifugation, concentration by fermentation, vaccum concentration, and spray drying. The economic feasibility of adding the fermentation operation to the present extraction and concentration operations was studied. Data were obtained on the production rate, pigment recovery, energy consumption (electrical, steam, gas), and pigment concentration at each unit operation. Calculations were based on a ton of raw beets processed. Energy costs were $15.57 per ton. The final spray dried colorant contained between 3 and 5% pigment depending on raw product quality. Byproducts of yeast and alcohol helped to offset 16% of the energy and raw product costs.     

Degradation of carrot (Daucus carota) fibres with cell-wall polysaccharide-degrading enzymes

Carrot Daucus carota L fibres were degraded with two enzyme preparations, SP249 from Aspergillus aculeatus and Celluclast from Trichoderma reesei. The enzymic activities of these complexes indicate that SP249 was particularly active on pectic polymers, and Celluclast could degrade amorphous and crystalline cellulose. A combination of both preparations degraded carrot fibres with a synergistic effect and led to the solubilisation of 95% of the cell-wall polysaccharides. The kinetics of solubilisation of sugars and gel-permeation chromatography of the soluble products show that pectic polymers were rapidly solubilised and then, in a second stage, degraded mainly to monomers, whereas cellulose was more slowly hydrolysed to cellobiose and glucose. Part (67%) of the polysaccharides were saccharified, the residual soluble material being rhamnogalacturonans containing arabinose residues. Residual insoluble fibres (10% of initial weight) were not liquefied and were composed mainly of lignin, proteins and polymers of glucose, xylose and galacturonic acid.     

不同贮藏时间普洱生茶水提物的特征性成分分析

以同公司、同批号、不同贮藏时间的普洱生茶(7542)为研究对象,真空冷冻干燥制备普洱生茶水提取物,利用分光光度计和超高效液相色谱-串联质谱(ultra performance liquid chromatography-tandem mass spectrometry,UPLC-MS/MS)检测其内含成分,并进行主成分分析(principal component analysis,PCA)和聚类分析(cluster analysis,CA),得出不同贮藏时间普洱生茶水提物的特征性成分和聚类树状图。结果表明,不同贮藏时间的普洱生茶水提物,随着贮藏时间的延长,茶多酚、儿茶素和游离氨基酸呈逐渐下降趋势,黄酮呈逐渐上升趋势,可溶性总糖和咖啡碱呈不规则变化;不同贮藏时间的普洱生茶提取物经UPLC-MS/MS共检测到107种化合物,经PCA,得到不同贮藏时间普洱生茶水提物的特征性成分包括柠檬酸、没食子酸、表儿茶素、茶氨酸、咖啡碱、表没食子儿茶素没食子酸酯等26种物质;CA表明,贮藏年份越接近的普洱生茶水提物样越易聚为一类,贮藏时间达到3 a和8 a时,茶叶聚类分类发生较大变化。     

Effect of Various Food Additives on the Levels of 4(5)‐Methylimidazole in a Soy Sauce Model System

In this study, the effect of food additives such as iron sulfate, magnesium sulfate, zinc sulfate, citric acid, gallic acid, and ascorbic acid on the reduction of 4(5)‐methylimidazole (4(5)‐MI) was investigated using a soy sauce model system. The concentration of 4(5)‐MI in the soy sauce model system with 5% (v/v) caramel colorant III was 1404.13 μg/L. The reduction rate of 4(5)‐MI level with the addition of 0.1M additives followed in order: iron sulfate (81%) > zinc sulfate (61%) > citric acid (40%) > gallic acid (38%) > ascorbic acid (24%) > magnesium sulfate (13%). Correlations between 4(5)‐MI levels and the physicochemical properties of soy sauce, including the amount of caramel colorant, pH value, and color differences, were determined. The highest correlations were found between 4(5)‐MI levels and the amount of caramel colorant and pH values (r² = 0.9712, r² = 0.9378). The concentration of caramel colorants in 8 commercial soy sauces were estimated, and ranged from 0.01 to 1.34% (v/v).     

Method for the estimation of available carbohydrate in foods

Several types of foods have been analysed for available carbohydrate, comprising free sugars, starch, dextrins and glycogen. The foods examined were meat pie, fish fingers, raw and cooked liver, canned soup, baked beans, yoghourt, cereal, green beans and biscuit. Free sugars were extracted from the foods with 80% (v/v) ethanol. After deproteinisation and deionisation, an aliquot of the purified extract was injected into the Technicon autoanalyser. In this system sugars are separated chromatographically as ionised borate complexes on an anion exchange column at 53°C. Following elution, sugars are determined by reaction with orcinol in sulphuric acid at 95° by measurement of the absorbance at 420 nm of the resulting yellow solutions.Starch, dextrins and glycogen, if present, were determined in the insoluble residue remaining after extraction of the free sugars. The use of the enzyme glucamylase allows the quantitative transformation of starch to glucose by a stepwise cleavage of ($\text{(α-}\text{d}\text{-(1 → 4}$) and ($\text{α-}\text{d}\text{-(1 → 6)}$) glucosidic linkages. The glucose was estimated with the specific enzyme glucose oxidase by colorimetry at 420 nm in the autoanalyser.     

Edible coating materials—their properties and use in the fortification of rice with folic acid

This study investigated the technical feasibility of adding folic acid on to rice and coating with edible polymers. The coating solutions were cast into film and their properties were investigated. A concentrated premix of rice was prepared in a rotating coating pan by spraying first with folic acid solution, and then with polymer solutions and drying. The fortified rice premixes were evaluated for washing and cooking losses. The loss of folic acid in washing was lowest in rice premixes coated with ethyl cellulose followed by pectin, composite mixtures of locust bean and other coating materials with highest loss in gum arabic coated rice. No edible polymer could satisfactorily retain folic acid during boiling in excess water. Edible polymers failed to mask the yellow color of folic acid and additional masking agent was needed. The premixes had a higher water uptake ratio than raw milled rice had. Triangle tests did not show any significant difference (=0.05) between the sensory qualities of cooked fortified rice and raw milled rice.     

Effects of colorant concentration and ‘natural colour’ or ‘sodium content’ claim on saltiness perception,consumer liking and emotion,and purchase intent of dipping sauces

Natural colorant (no colorant, NC = 0%; moderate colorant, MC = 1.2%; high colorant, HC = 3.6% w/w) and salt (regular salt, RS = NaCl; reduced sodium, ReS = KCl; no salt, NS) were added in mayonnaise‐based dipping sauces to evaluate effects of colorant concentration and ‘natural colorant’ or ‘sodium content’ claim on saltiness expectation, consumer liking and emotion, and purchase intent (PI) of these products. Regardless of the salt type and content, increasing colorant concentration decreased colour liking scores while saltiness expectation tentatively increased as indicated by higher % of ‘too much’ responses for saltiness on a JAR (Just‐About‐Right) scale. At a given salt type and content, liking scores of salty taste decreased with increasing colorant concentration, both before and after the ‘sodium content’ claim was given to consumers. Emotion scores elicited by consuming dipping sauces were affected by colorant concentration. Positive emotions (good, interested, satisfied) decreased while negative emotions (guilty, unsafe, worried) increased with increasing colorant concentration. Statements of ‘natural colorant’ and ‘sodium content’ claim had minimal effects on elicited emotions and PI.     

Analysis of factors affecting volatile compound formation in roasted pumpkin seeds with selected ion flow tube-mass spectrometry (SIFT-MS) and sensory analysis

Pumpkin (Cucurbita pepo and maxima) seeds are uniquely flavored and commonly consumed as a healthy roasted snack. The objective was to determine dominant volatiles in raw and roasted pumpkin seeds, and the effect of seed coat, moisture content, fatty acid ratio, total lipids, reducing sugars, and harvest year on volatile formation. Sensory was conducted to evaluate overall liking of seed variety and texture. Seed processing included extraction from the fruit, dehydration, and roasting (150 °C). Oil extraction was done using soxhlet, fatty acid profile using Gas Chromatography Flame Ionization Detector, and reducing sugars using 3,5-dinitrosalicylic acid and UV-spectroscopy. Headspace analysis of seeds was performed by selected ion flow tube-mass spectrometry (SIFT-MS). Volatiles dominating in raw pumpkin seeds were lipid aldehydes, ethyl acetate, 2,3-butandione, and dimethylsulfide. Compounds contributing to roasted aroma include alkylpyrazines and Strecker and lipid aldehydes. Overall, hull-less seeds had higher volatile lipid aldehydes and Strecker aldehydes. Seeds dehydrated to a moisture content of 6.5% before roasting had higher initial and final volatile concentrations than seeds starting at 50% moisture. Higher oil content resulted in higher lipid aldehyde formation during roasting with a moderate correlation between free fatty acid ratio and corresponding lipid aldehyde. Harvest year (2009 compared with 2010) had a significant impact on volatile formation in hull-less seeds, but not as much as variety differences. No significant correlation was found between reducing sugars and volatile formation. Sensory showed that hull-less seeds were liked significantly more than hulled seeds. PRACTICAL APPLICATION: Elucidation of aromatic flavor development during roasting with SIFT-MS provides information on flavor release and offers better control during processing. Knowledge of volatiles in raw and roasted pumpkin seeds and effects of seed coat, moisture content, seed composition, and harvest date will allow for better control over the production/storage/transportation process and a more educated decision during selection of a variety for production of pumpkin seeds in the snack food industry.     

酵母细胞壁多糖分子量分布和结构的初步分析

以啤酒酵母细胞壁多糖为研究对象,比较了Sevage法和三氯乙酸（TCA）法脱蛋白效果,利用凝胶渗透色谱法（GPC）测定了细胞壁多糖的分子量分布,用葡聚糖凝胶G-100对多糖进行了纯化,最后用红外光谱法分析了多糖组分D的结构,结果表明:Sevage法脱蛋白效果较好,GPC测定结果得出酵母细胞壁多糖有5个组分,其重均分子量为1.31745×105、7.0863×104、3.6988×104、1.8277×104、8.342×103。红外光谱分析得出多糖组分D在890.51cm-1和808.48cm-1有特征吸收,为β-D-吡喃型结构,在844cm-1处没有吸收峰,不含有或含有少量的α-型糖苷键。