Image analysis of skin colour using independent component analysis and its application to melanin pigmentation analysis

Generally, hydrophilic surfactants are added to make a small particle size liposome. However, there is a problem that a small particle size liposome causes a decrease of its capacity in the internal water phase, and it cannot function well enough as a capsule. Therefore we investigated the effect of various surfactants and lipids on superfine liposome. Firstly, we examined some hydrophilic surfactants which have different molecular structures to minimize the liposomes. PEG-25 phytostanol ether was most effective to make particle size small among non-ionic hydrophilic surfactants. However, as the particle size got smaller, its capacity in the internal water phase decreased, being transformed into the micelles. Secondly, we tried to increase the capacity of the internal water phase by adding the combined lipid into the liposome membrane. It was indicated that phytosterol had the potential to increase remarkably the internal water phase. As a result, we found that it's possible to make a liposome of a small particle size having a large capacity in the internal water phase by using both PEG-25 phytostanol ether and phytosterol. Furthermore, the superiority of the liposome which consisted of the above ingredients in electrolyte-resistance was confirmed.     

Development of a kinetic model for L-lysine biosynthesis in Corynebacterium glutamicum and its application to metabolic control analysis

A mathematical model describing intracellular lysine synthesis by Corynebacterium glutamicum in batch fermentation was developed. The model is based on material balance equations of the key metabolites, and includes mechanistically based, experimentally matched rate equations for individual enzymes. From the measurements of the levels of intra- and extracellular metabolites during cultivation, the kinetic parameters in the model were identified through the decomposition of the network of reactions. The model predictions and experimental observations were in reasonable agreement. Using the model developed, metabolic control analysis was carried out to identify the rate-limiting steps, by evaluating the control on the overall lysine synthesis flux exerted by individual enzymatic reactions, which suggested how the control on lysine synthesis changes from aspartokinase to lysine permease as fermentation proceeded and indicated that lysine production could be enhanced by improving aspartokinase activity of this strain through genetic manipulation.     

响应面试验优化黄豆酱工艺条件及其色泽质构分析

以黄豆、小麦面粉为原料,采用混合菌种发酵制备黄豆酱,利用Box-Behnken响应面试验优化其工艺条件,并对黄豆酱的色泽与质构进行测定和分析。结果表明,最佳发酵工艺条件为121 ℃蒸煮黄豆16 min,湿黄豆与面粉质量比10∶3,发酵温度36 ℃。在此优化条件下,黄豆酱还原糖、氨基酸态氮含量分别为10.96%、0.76 g/100 g。在121 ℃条件下,随黄豆蒸煮时间在5～14 min、湿黄豆与蒸熟的面粉质量比在10∶1～10∶5及发酵温度在25～45 ℃范围变化,黄豆酱L*值及b*值逐渐下降,a*值逐渐上升,其色泽均匀,有光泽,逐渐加深最终为红棕色;黄豆酱的硬度与咀嚼性减弱,黏着性增强,其组织状态良好,质地细腻,黏稠适度,软硬适当,具有很好的咀嚼感。     

Development of 4-hydroxyproline analysis kit and its application to collagen quantification

4-Hydroxyproline (4-Hyp) is a specific amino acid of collagen and widely used as a factor to estimate the collagen content in biological specimens. The authors have developed an analysis kit with the ability to detect collagen on microwells. The method includes chromophore formation without solvent transfers, that allows the analysis of multiple specimens with excellent sensitivity, high specificity at low cost with shorter analysis time. The calibration curve of 4-HYP kit exhibiting a high positive relationship (R² = 0.999) while showing a very low detection limit of (1.0 μg/ml). Specificity of 4-HYP kit was decreased with increasing hydrolysed non-collagenous biomolecules (HNCB), however this was negligible since only a few collagen specimens have a high amount of HNCB. The 4-HYP kit was successfully applied to commercial collagen quantification, measuring the collagen content of connective tissue and collagen synthesis of fibroblast with high satisfactory results; therefore, this is a more suitable alternative to previous analysis methods.     

The use of video image analysis for quantitative measurement of visible fat and lean in meat: Part 4- application of image analysis measurement techniques to minced meats

The quantitative measurement of fat in minced meat by video techniques has, to date, been impractical due to the nature of the raw material and camera limitations in particle resolution. The latter have been enhanced by improving the optical system and by illuminating the meat with a limited wavelength ultraviolet light source. Problems with fat smear and drip stain, causing over- and under-estimation of fat, respectively, have been overcome by better control of mincing conditions. Tempering of the meat to between -2°C and -5°C before mincing gave the best results. The level of fat detection was unchanged for up to 20 min after mincing, but, by 2 h, the initial value had fallen by 50%. Magnifying the field of view, thus reducing the sample size measured by 50%, did not adversely affect results with 4mm-10mm diameter mince. The system could not accurately resolve mince below 4 mm. Estimation of total lipid from video data using prediction equations was in good agreement with chemical analysis (r=0·99 for 10mm mince, r=0·95 for 4 mm mince). Video image analysis (VIA) can now be effectively extended to areas of meat processing using particulate meats.     

芒果TPA质构测定优化及不同成熟度芒果质构特性分析

应用质构仪对芒果果肉进行TPA测试,探索压缩率、测试方向、测试速率等测试条件对不同成熟度芒果果肉质构测定结果的影响。结果表明,三种测试条件对不同成熟度芒果果肉的质构测定影响不同,采用果皮面向探头,测试和测后速率均为1 mm/s,压缩率20%~30%的测试条件能较好的表征芒果果肉的TPA质构特性。在芒果成熟过程中,随样品成熟度的增加,硬度、凝聚性、咀嚼性迅速下降,粘着性以成熟度2级最高,弹性变化不大;低成熟度芒果果肉质构参数的相关性较好,硬度和咀嚼性呈显著正相关性,高成熟度的芒果各质构参数间相关性不显著。本研究为质构仪应用于芒果果肉质构测定提供了参考。      

电子鼻及其在食品分析中应用研究进展

电子鼻作为一种嗅觉传感器技术,以其客观性、可靠性和重现性等优点在食品分析中得到广泛应用。该文在介绍电子鼻工作原理及基本组成基础上,就其在国内外食品品质监控、食品评价、食品安全检测方面一些应用进行综述,以期对改善我国食品分析现状提供有益参考。     

Development and application of image analysis to quantify calcium lactate crystals on the surface of smoked Cheddar cheese

Calcium lactate crystals that form white specks or haze on the surface of cheese constitute a significant quality problem for producers of Cheddar cheese. Subjective methods to evaluate crystal coverage of cheese surfaces have been reported previously, but objective methods are currently lacking. The objectives of this work were to develop and evaluate an objective method to measure the area occupied by calcium lactate crystals on surfaces of naturally smoked Cheddar cheese samples using digital photography and image analysis. Coefficients of variation ranged from 1.29 to 4.68% for 5 replicate analyses of 3 different cheese surfaces that ranged from ∼2 to 49% of total surface area occupied by crystals. Thus, results showed a high degree of repeatability for the 3 cheese surfaces, which ranged from very slight and geometrically simple to very heavy and geometrically complex crystal coverage. The method underestimated total area occupied by crystals on the 3 surfaces by 0.24 to 4.83% unless the fainter crystal regions that went undetected during initial thresholding were manually segmented and quantified. The wet weight of crystal substance collected per unit of surface area from 20 different cheese samples increased exponentially as the percentage of total surface area occupied by crystals increased. These data were consistent with subjective observations that crystal regions appeared to grow vertically as well as horizontally as they expanded to occupy greater surface area. Image analysis was well suited for evaluating changes in crystal coverage during cheese aging because measurements were made nondestructively and with minimal disruption to the cheese. The area occupied by crystals on 6 different surfaces from 3 different cheese samples increased linearly (R² = 0.94 to 0.99) during storage at 4°C for up to 33 wk. However, the rates of increase differed significantly among the 3 cheese samples. Image analysis may serve as a useful tool to quantitatively evaluate the effects of factors such as cheese composition, packaging conditions and storage temperature on rate of crystal growth and time of crystal appearance during storage.     

Changes in surface configuration of the skin caused by ageing and application of cosmetics: three-dimensional analysis according to a new system based on image analysis and Fourier transformation

The surface configuration of the skin, as characterized by surface furrows and plateaux, is known to change with ageing and skin condition. There have been many attempts to analyse the surface configuration in order to evaluate the effect of skin care products. However, the systems proposed up to now are insufficient to obtain three-dimensional data.
A system based on image analysis and Fourier transformation has been developed. By using this system, we can make a quick and quantitative analysis of the three-dimensional surface configuration of the skin. This system was applied to measure changes in the surface configuration with ageing, and to clarify the effects of cosmetic cream.
As a result, it was found that the furrows become less clear, become parallel in one direction and the texture becomes coarse and irregular, as ageing continues. These changes are believed to correspond to deterioration of the metabolic and moisturizing functions of the skin.
It was also found that the furrows become clear and the texture becomes finer after the application of cream than before. This is believed to be the result of the improvement of the skin condition due to the moisturizing effect of the cream.     

米酵菌酸荧光定量检测卡的开发和应用

目的开发一种快速定量检测米面等食品中米酵菌酸的方法。方法首先,制备米酵菌酸-牛血清白蛋白偶联物(bongkrekic acid-bovine serum albumin, BA-BSA),作为检测卡的包被原料包被至硝酸纤维素膜上,用本公司自制BA单克隆抗体与时间分辨微球标记放入微孔中,然后将包被后的膜和标记后的微孔组装成快速检测卡。结果快速检测卡的线性范围为1～100 ng/mL,前处理采用碱性甲醇水溶液提取样本中米酵菌酸。结论本方法快速、准确、灵敏度高,适合样品中米酵菌酸的检测。     

Portable erythema meter and its application to use in human skin

In this study a compact, hand-held, solid state erythema meter using light emitting diodes is described. This device has been constructed and used to compare with visual assessments of ultraviolet radiation in human subjects. A statistically significant correlation was obtained between erythema index and visual assessment in 24 ultraviolet irradiated subjects. Furthermore, the effects of three aftersun treatments have also been assessed objectively using the meter and subjectively using visual assessments. The ultraviolet-irradiated areas were less red following treatment than the irradiated and untreated areas. The results obtained by the meter were similar to and statistically significant with those obtained by visual assessment.
It is concluded that widespread use of an erythema meter such as that described would greatly improve all cutaneous erythema assessments.     

蛹皮壳聚糖的制备及在毛织物艾蒿染色中的应用

以柞蚕蛹皮为原料制取壳聚糖,并用该壳聚糖预处理羊毛织物进行染色,探讨壳聚糖预处理对羊毛织物染色性能的影响。柞蚕蛹皮采用稀盐酸、稀氢氧化钠进行脱钙、脱脂肪制备甲壳素,采用浓氢氧化钠溶液脱乙酰基,双氧水脱色工艺,制备脱乙酰度90%的乳白色壳聚糖产品,并用正交试验法优化脱乙酰基工艺。结果表明,甲壳素脱乙酰基的最佳工艺为:氢氧化钠质量分数50%,处理温度100℃,时间9 h,甲壳素与碱液质量比1∶20;经壳聚糖预处理后,羊毛织物艾蒿染色的染色深度明显提高,皂洗和摩擦色牢度基本不变。     

乳酸及其盐在表面技术中的应用

本文讲述了乳酸及其盐类在镀镍、镀金、化学镀镍和其他表面处理（催化、镀前处理）几方面的应用，提出了使用乳酸应该注意的问题，还列出了13篇参考文献。     

多重基因遗传表达分析系统及其应用研究进展

核酸检测技术广泛用于生命科学、微生物学及医学领域。随着分子生物学的发展,在经典技术的基础上研究人员又开发出多种新型检测技术。其中多重基因遗传表达分析系统(gene expression profiler genetic analysis system,Ge XP)技术作为聚合酶链式反应和芯片的换代技术,具有特异性好、灵敏度高的特点,能够同时检测多个目的基因,真正意义上实现了高通量检测。本文详细介绍了Ge XP技术的原理以及优缺点,并对Ge XP技术在畜牧兽医研究、转基因食品检测、微生物检测及医学研究中的应用进行阐述,以期为该技术将来在食品检测方面的推广提供参考。     

Development of a quantitative method for headspace analysis of methylsulfanyl-volatiles from kiwifruit tissue

Minor fruit volatiles are likely to be missed using sampling techniques optimized for the extraction of major compounds. This can be a disadvantage if these minor compounds contribute to characteristic fruit flavors. In this comparative study, headspace solid-phase microextraction (HS-SPME) and dynamic headspace sampling (DHS) parameters were systematically optimized to ensure highest extraction yields of methylsulfanyl-volatiles from kiwifruit tissue samples. A significant “salting-out” effect from the fruit matrix was observed using both sampling techniques after (NH₄)₂SO₄ saturation. HS-SPME at optimized conditions (polydimethylsiloxane-divinylbenzene-coated fiber, (NH₄)₂SO₄ saturation, 5 min equilibration and 20 min sampling at 40 °C) was faster and more convenient to use than DHS for qualitative purposes. Despite this, the qualitative and quantitative methylsulfanyl-volatile profile was improved using optimized DHS ((NH₄)₂SO₄ saturation; sampling time 20 h; flow rate 30 mL min^− 1) compared with HS-SPME, making this the more sensitive and preferred method for quantitative studies. The optimization strategies for increasing headspace extraction yields of trace compounds presented in this study can easily be applied to tissue samples from other fruit.