不同条件下乌桕类可可脂结晶行为之研究

液化后的CTCBE如果在室温下自然缓慢冷却凝固则导致容器以横向力炸裂，而以冷冻方式使之快速冷却固化，则容器完好无损，CB则不会出现类似情况。为了解这一现象与CTCBE结晶行为的关系，拟用X粉末衍射和差示扫描量热法对乌桕类可可脂和天然可可脂在不同条件下的结晶行为进行了研究。结果表明过 冷度和诱导晶核对乌桕类可可脂和天然可可脂的结晶行为有不同的影响。对乌桕类可可脂而言，过冷度对有诱导晶核存在的结晶行为无明显影响，相反对无诱导晶核的结晶行为则有较大影响。天然可可脂则不然，过冷度的变化对有或没有诱导晶核存在的结晶行为均有很大影响；如果过冷度相同，则有或没有诱导晶核存在的结晶行为无太大差异。     

月桂酸类代可可脂巧克力脂霜组成及形态学研究

通过气相色谱分析和显微镜观察对起霜前后月桂酸类代可可脂巧克力的脂肪酸组成以及形态学特征进行了研究。结果表明,与新鲜巧克力相比,脂霜中C12∶0、C18∶0、C18∶1含量明显增加,而C14∶0含量相对减少;原子力显微镜结果显示,新鲜巧克力表面相对平滑,起霜后平滑表面破坏,形成明显凹凸面;扫描电镜观察发现新鲜巧克力表面结晶网络结构疏松,起霜巧克力表面油脂晶体形成致密网络结构;偏光显微镜显示脂霜中晶体颗粒明显大于新鲜巧克力晶体颗粒,发生了向更稳定晶体的转变。     

Cocoa butter fats and possibilities of substitution in food products concerning cocoa varieties,alternative sources,extraction methods,composition, and characteristics

The current concern for cocoa butter fat as major ingredients of chocolate intake in the World has raised the question of the high price of cocoa butter among all other vegetable fats. Productions of natural cocoa butter fats are decreasing day by day due to the decrease of cocoa cultivation worldwide; moreover, cocoa fruit contains only a little amount of cocoa butter. Therefore, the food industries are keen to find the alternatives to cocoa butter fat and this issue has been contemplated among food manufacturers. This review offers an update of scientific research conducted in relation to the alternative fats of cocoa butter from natural sources. The findings highlights how these cocoa butter alternatives are being produced either by blending, modifying the natural oils or fats from palm oil, palm kernel oil, mango seed kernel fats, kokum butter fat, sal fat, shea butter, and illipé fat.     

Influence des ions sur le pouvoir hydratant de l'ure e: e tude sur peau de porc ex vivo

This study deals with the influence of ions (NaCl and MgSO4) in a W/O emulsion containing 10% urea. Moisturization kinetics are assessed by corneometry on pig skin ex vivo. The formula's influence on urea penetration is measured by infrared spectrometry with an ATR device and the stripping method. Corneometry and spectroscopy were chosen to record simultaneously the hydratation levels and urea localization into superficial cell layers. Urea crystallization after evaporation of emulsions and aqueous solutions is described. Results show that urea does not hydrate nor penetrate when applied to the skin through an aqueous gel. In a W/O emulsion, sodium chloride increases the ability of urea to moisturize without improving penetration. In vitro urea crystallization is disturbed by sodium chloride or magnesium sulphate for solutions and emulsions. This stabilization by ions is correlated with good moisturization values. The stabilization of urea in the solute state provided by ions increases its water epidermal binding capacity without enhancing penetration.     

Non-saponifiable fraction of cocoa shell butter: effect on rat and human skin fibroblasts

Non-saponifiable lipid fraction (ICSB) extracted from cocoa shell butter was solubilized in dimethylformamide (DMF) and analysed for its biological activity on growth of rat and human fibroblasts. Non-saponifiables (10 μg ml⁻¹) partially protected cells from toxicity of DMF (1%) and allowed the growth of fibroblasts cultivated in optimal conditions (10% fetal calf serum-FCS, 37°C) or improved the survival of cells maintained in altered conditions (2.5% FCS, 35°C). At higher concentration (ICSB 50 μg ml⁻¹, DMF 1%), the protective effect was suppressed. ICSB was fractionated by chromatography into four compounds: sterols, terpenic alcohols, tocopherols and hydrocarbons ± carotenoids. We found that biological activity of ICSB was mostly due to the major fraction containing sterols.     

Glycation induction and antiglycation activity of skin care ingredients on living human skin explants

Glycation is an ageing reaction of naturally occurring sugars with dermal proteins, whose clinical signs may appear in vivo around age 30, and increases steadily/regularly with age. The suppleness of the dermis is affected by the formation of bridges between proteins and sugars (Maillard's reaction). The residues formed (Amadori products, Advanced Glycation End products) as well as the proteins they alter, can be visualized by specific immunostainings. Induced in a few days on living skin explants by methylglyoxal, glycation can be prevented by the application of aminoguanidine HCl, the reference anti-glycation molecule. This model enabled to highlight the anti-glycation activity of substances of vegetal origin such as puerarin and chlorogenic acid.     

发酵和焙烤对可可豆多酚、黄酮和风味品质的影响

本实验采用高效液相色谱仪（high performance liquid chromatography,HPLC）、色差仪、电子鼻分别检测未发酵、发酵和焙烤海南可可豆的总酚含量、总黄酮含量、色度和可可豆风味差异。结果表明：未经焙烤的未发酵豆总酚（464.03 mg/10 g）和总黄酮（126.86 mg/10 g）含量明显高于发酵豆总酚（211.86 mg/10 g）和总黄酮（61.98 mg/10 g）含量。105～145 ℃焙烤30 min,未发酵豆总酚和总黄酮含量分别为419.5～129.8 mg/10 g和77.8～16.8 mg/10 g;发酵豆总酚和总黄酮含量分别为182.53～86.25 mg/10 g和34.7～7.0 mg/10 g。其中,125 ℃焙烤20～40 min,未发酵豆总酚和黄酮含量分别为353.74～289.45 mg/10 g和42.86～32.20 mg/10 g;发酵豆总酚和黄酮含量分别为152.08～123.55 mg/10 g和25.12～21.14 mg/10 g。在105～145 ℃的温度焙烤下没食子酸含量变化显著。可可豆色度值的范围：L*值集中在40.0～47.0之间,a*值集中在5.0～6.8之间,b*值集中在4.0～8.5之间。未发酵和发酵可可豆之间,以及不同温度焙烤可可豆之间的电子感官风味分析结果差异较大。     

花生红衣多酚类物质的制备及其抗氧化活性研究进展

花生红衣是花生加工过程中的廉价副产品,含有丰富的酚类物质,具有良好的抗氧化活性。本文在对花生红衣多酚文献分析统计的基础上,综述了花生红衣多酚类物质水提法、有机溶剂提取法、超声波辅助提取法、微波辅助提取法、酶辅助提取法和闪式提取法等制备方法,有机溶剂萃取法、大孔树脂分离法和膜分离法等分离纯化方法及组分分析方法,抗氧化活性评价方法以及其在食品工业中的应用,并对其研究中的重点和存在的问题进行了总结和展望。     

Physical and antibacterial properties of edible films formulated with apple skin polyphenols

Fruit and vegetable skins have polyphenolic compounds, terpenes, and phenols with antimicrobial and antioxidant activity. These flavoring plant essential oil components are generally regarded as safe. Edible films made from fruits or vegetables containing apple skin polyphenols have the potential to be used commercially to protect food against contamination by pathogenic bacteria. The main objective of this study was to evaluate physical properties as well as antimicrobial activities against Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella enterica of apple skin polyphenols at 0% to 10% (w/w) concentrations in apple puree film-forming solutions formulated into edible films. Commercial apple skin polyphenol powder had a water activity of 0.44 and high total soluble phenolic compounds and antioxidant capacity (995.3 mg chlorogenic acid/100 g and 14.4 mg Trolox/g, respectively). Antimicrobial activities of edible film containing apple skin polyphenols were determined by the overlay method. Apple edible film with apple skin polyphenols was highly effective against L. monocytogenes. The minimum concentration need to inactive L. monocytogenes was 1.5%. However, apple skin polyphenols did not show any antimicrobial effect against E. coli O157:H7 and S. enterica even at 10% level. The presence of apple skin polyphenols reduced water vapor permeability of films. Apple skin polyphenols increased elongation of films and darkened the color of films. The results of the present study show that apple skin polyphenols can be used to prepare apple-based antimicrobial edible films with good physical properties for food applications by direct contact.     

香菇、茶叶抗类可可脂巧克力脂霜之形态学研究

用偏光显微镜和扫描电镜在形态学方面就香菇和茶叶抗类可可脂巧克力脂霜进行了研究 ,电镜结果表明 ,香菇和茶叶巧克力的质构呈链状有规则排列 ,而对照样则呈杂乱零星无规则排列。偏光显微结果说明 ,无论是起霜还是未起霜的香菇和茶叶巧克力 ,其晶相均呈有规律的均匀分布 ,而对照样则无规则性可言。在相同的促霜时间内 ,对照样起霜程度比香菇和茶叶巧克力大     

Infrared and Raman imaging spectroscopy of ex vivo skin

This primer describes and illustrates experimental protocols for both Fourier transform infrared (FTIR) spectroscopic imaging and confocal Raman mapping of ex vivo skin and thereby acquaints the reader with these measurement techniques, including the temporal and spatial limitations associated with each technique. The experimental conditions by which the unique ‘molecular histology’ information obtained from confocal Raman mapping and infrared spectroscopic mapping of ex vivo skin is generated will be described. Raman and FTIR spectra of tissue, when collected in spatially resolved arrays, permit the generation of ‘molecular images’ of tissue components and tissue organization without the use of fluorescent labels or chemical stains. To illustrate the molecular information from ex vivo skin that can be spectroscopically imaged with confocal Raman and infrared microspectroscopy, we have collected new data using both techniques and generated spectral images which illustrate the capacity of each technique to provide unique insights into skin histology, biochemistry and biophysics. Understanding the measurement possibilities and specific constraints of both approaches is a prerequisite to their meaningful use as powerful research tools in skin research.     

茶与葡萄皮总多酚的提取、纯化及抗氧化活性

本研究以乌龙茶与葡萄皮为研究对象,在单因素实验基础上,采用Box-Behnken实验设计以及响应面分析对乙醇浸提乌龙茶与葡萄皮总多酚的工艺进行优化,再以NKA9型大孔树脂纯化,测定纯化多酚的还原力以及羟自由基清除率,评价其抗氧化活性强弱。结果表明:总多酚提取最佳工艺条件为温度88℃,乙醇浓度48%,液料比22∶1（m L/g）,时间40min,总多酚的得率可达4.76%,理论预测为4.79%,相差0.62%,响应面优化的回归方程有一定实践指导意义。NKA9型大孔树脂纯化精制后多酚含量由25.54%提高至82.19%。以抗坏血酸作对照,测定精制多酚的还原能力和羟自由基消除能力,精制乌龙茶与葡萄皮总多酚的还原力和羟自由基消除能力均优于同浓度的抗坏血酸,总多酚对·OH的消除率达50%时的浓度IC50为17.60μg/m L,抗氧化活性较好。      

Industrially important parameters and mineral composition of cocoa: A comparative study of cocoa pod husks and beans from plantations in south-eastern Nigeria

The industrially significant parameters of cocoa butters from the F₃ Amazon, Amelonado, and Trinitario species of cocoa, cultivated in south-eastern Nigeria were studied. The cocoa samples were collected from three different vegetation belts in the region. Three locations were selected to represent each of the belts selected for the study. There were no substantial variations in saponification values, iodine values, acid and fatty acid values, either among species or among locations. The Ca, Na, K and P contents of the husks were substantially higher than those of the beans for all species and all locations. For each of these elements there appeared to be an effect of location, which is the subject of continuing investigation. The pod husk appears to be a good source of P and K which might be used to supplement other sources of these minerals as plant nutrients.     

Image analysis to quantify histological and immunofluorescent staining of ex vivo skin and skin cell cultures

Image processing steps and analysis techniques were developed for the quantification of photomicrographs obtained from light and fluorescence microscopy. The substrates examined were either skin cell cultures, such as normal human keratinocytes (NHK) or fibroblasts, or ex vivo skin sections. Examples of the analyses are provided for the comparison of skincare active ingredient treated samples vs. placebo to demonstrate the utility of the methods to quantify and provide numerical data for a procedure that is typically qualitative in nature and based on observations by a histologist. Quantifiable experiments that are discussed include: Fontana Masson staining for melanin expression; Nile red staining to detect cellular lipid droplets; nuclei staining with diamidino‐phenylindole (DAPI); and immunofluorescent staining of protein expression with a primary antibody directed against the protein (antigen) and a secondary antibody tagged with a fluorescent dye (Alexa Fluor 488) against the primary antibody.     

Comparative analysis of solar radiation-induced cellular damage between ex vivo porcine skin organ culture and in vitro reconstructed human epidermis

Reconstructed human epidermis models (RHE) constitute an innovative alternative to study phototoxicity and photoprotection in the cosmetic industry. However, little information is currently available concerning the harmful effects of solar-simulated radiation (SSR) in these in vitro skin models. In this study, the phototoxic effects of a single acute SSR dose of 275 kJ m⁻² were evaluated in a validated RHE model (from SkinEthic), and were compared with those obtained from an ex vivo skin organ culture recently developed from domestic pig ears. The RHE model was well differentiated in vitro and released a significant level of the cytosolic enzymes lactate dehydrogenase (LDH) and extracellular signal-related kinase 2 (ERK2) protein in the culture medium 24 h after SSR exposure. The SSR-induced cytotoxicity was related to the formation of sunburn cells and the appearance of DNA damage (thymine dimer and DNA fragmentation) in keratinocytes. Interestingly, these DNA alterations were associated with the activation of the caspase-3 protease, mainly in the basal layers of the epidermis. In addition, the RHE model responses were comparable with porcine skin following solar irradiation, and none of the above cellular responses was observed in non-irradiated skin models. Finally, topical application of a broad-spectrum UVB + A sunscreen formulation efficiently protected both the RHE and pig skin against the deleterious effects of SSR. Thus, both RHE and ex vivo pig skin organ culture models are complementary tools in the assessment of SSR-induced DNA damage and apoptosis, and they may be used to evaluate the photoprotective capacity of cosmetic formulations.     

Evaluation of the Ability of Polyphenol Extracts of Cocoa and Red Grape to Promote the Antioxidant Response in Yeast Using a Rapid Multiwell Assay

Saccharomyces cerevisiae has been used as a model organism to study the capacity of cocoa and red grape extracts to trigger an antioxidant response. A methodology adapted to microtiter plates has been developed to monitor yeast growth after culture preincubation with food ingredients and exposure to oxidative stress by hydrogen peroxide and menadione. This methodology proved effective in measuring the ability of cocoa and red grape extracts to promote an antioxidant response in yeast, and also the prospect of conducting dose–response studies. Additionally, the method has proven useful to perform studies with mutant strains lacking genes that may be related to the mechanism of action underlying the antioxidant properties. Thus, in a single assay, it is possible to elucidate the sensitivity of strains to oxidative stress, the ability of an ingredient to promote an antioxidant response, and the possible implication of certain genes. Results of assays using strain hst3Δ showed that the antioxidant protection provided by exposure to cocoa and red grape extracts was not present in the strain lacking gene HST3 when H₂O₂ and menadione were used as oxidizing agents. This effect was previously reported for cocoa extract only, with H₂O₂ as stressor. Moreover, the results showed that the mutant strain hst3Δ is more resistant to menadione and H₂O₂ in the absence of preincubation with cocoa and red grape extract, hinting at the possible implication of sirtuin Hst3 in the antioxidant cellular response.