烘烤对肉制品中多环芳烃和杂环胺含量的影响

烘烤是肉制品加工中重要的工艺之一,但经烘烤的肉制品中含有多环芳烃、杂环胺等有害物质,对消费者的健康造成很大的威胁.介绍了多环芳烃、杂环胺及其对人体的危害,重点阐述了烘烤对肉制品中多环芳烃和杂环胺含量的影响及其控制方法.     

Silicones: use of substantive properties on skin and hair

Silicones have been incorporated in personal care products since the 1950s. Initially used in skin care products, and more recently in hair care applications, silicones are recognized for their lubricating properties and for the characteristic soft smooth feel they impart. With recent advances in silicone technology, these fluids can also provide substantivity and durability.
Resinous silicones such as trimethylsiloxysilicate act as effective substantivity additives when combined with dimethyl silicone in skin care formulations. In tests evaluating the number of wash cycles required to penetrate a silicone barrier, resistance to removal increases markedly as the proportion of resinous silicone to dimethyl silicone is increased. This improvement is related directly to decreased solubility of the resin.     

Synthesis of 2-N-oleoylamino-octadecane-1,3-diol: a new ceramide highly effective for the treatment of skin and hair

2-N-Oleoylamino-octadecane-1,3-diol is a new synthetic ceramide. The process enables a four-step preparation of 2-amino-octadecane-1,3-diol (D,L-erythro/threo) and a five-step synthesis of 2-N-oleoylamino-octadecane-1,3-diol (D,L-erythro/threo). The latter compound is related to ceramide 2 according to the classification of Downing. This route of synthesis is rapid, reproducible and uses low-cost starting materials. The new ceramide was analysed as follows: ¹H, ¹³C, ¹⁵N NMR spectra afforded an unambiguous characterization of the structure; additionally, these three methods identified the threo and erythro isomers. ¹H and ¹³C NMR permitted the measurement of the threo/erythro ratio (26.6/73.4 and 25.5/74.5, respectively). Chemical ionization mass spectrometry confirmed the expected mass of the pseudo-molecular ion (m/z= 566.5: [M + H]⁺) as well as the presence of different chain lengths other than the oleic moiety due to the fatty acid composition of the technical grade oleic acid used for the synthesis. Capillary gas chromatography measured the threo/erythro ratio (23.5/76.5) which agrees with the ¹H and ¹³C NMR data. Moreover, this method afforded the relative distribution of the different N-acylated chains. The properties of the new synthetic ceramide for the treatment of skin and hair were mainly assessed by two in vitro methods. The first measured the flux of water through lipid-extracted stratum corneum. The described ceramide showed high efficacy in decreasing water loss. The second recorded the friction coefficient of different types of hair: virgin, permanent-waved, and bleached. Treatment by the ceramide led to a strong decrease in this coefficient. This was particularly observed on unrinsed hair. These findings suggest two potential fields of application and beneficial contribution for the new ceramide: repairing the barrier to transepidermal water loss, and improving the surface properties of hair. Synthèse du 2-N-oleoylamino-octadécane-1,3-diol: nouveau céramide à haut potentiel dans le soin de la peau et du cheveu.     

A review of ageing and an examination of clinical methods in the assessment of ageing skin. Part 2: Clinical perspectives and clinical methods in the evaluation of ageing skin

With the advancement of skin research, today's consumer has increased access to technological information about ageing skin and hair care products. As a result, there is a rapidly increasing demand for proof of efficacy of these products. Recognizing these demands has led to the development and validation of many clinical methods to measure and quantify ageing skin and the effects of anti-ageing treatments. Many of the current testing methods used to research and evaluate anti-ageing product claim to employ sophisticated instruments alongside more traditional clinical methods. Intelligent use of combined clinical methods has enabled the development of technologically advanced consumer products providing enhanced efficacy and performance. Of non-invasive methods for the assessment and quantification of ageing skin, there is a plethora of tools available to the clinical researcher as defined by key clinically observed ageing parameters: skin roughness and surface texture; fine lines and wrinkles; skin pigmentation; skin colour; firmness and elasticity; hair loss; and proliferative lesions. Furthermore, many clinical procedures for the evaluation of ageing skin treatments are combined with invasive procedures, which enable added-value to claims (such as identification and alteration of biochemical markers), particularly in those cases where perception of product effect needs additional support. As discussed herein, clinical methods used in the assessment of skin ageing are many and require a disciplined approach to their use in such investigations.     

Effect of germinated seeds extract on the respiratory activity of human skin fibroblasts and sheep liver mitochondria. Influence on cell viability and proliferation and their uselfulness as active cosmetic ingredient

The present work studies the ability of a germinated seeds extract (alfalfa, radish, wheat, soy) to influence cell respiration of skin fibroblasts and the respiratory activity of sheep liver isolated mitochondria, and the cytotoxicity of the product on cultured skin fibroblasts. The content of free and total amino acids present in this extract was determined. Aspartic acid represented 37.52% of free amino acids in the extract, but 48.07% glutamic acid was found when total amino acids obtained by acid hydrolysis were quantified. The extract contains more than 6.5% free serine, glutamic acid and alanine. Arginine, serine, aspartic acid and threonine are the other amino acids that represent more than 4.5% total amino acids. Respiration of sheep liver mitochondria and human skin fibroblasts (Foreskin ATCC CRL-1635) was checked polarographically. The results obtained show the ability of this extract to stimulate cellular respiration of both in vitro models, but the effect is more marked on cell cultured fibroblasts, and its dose dependency. The role of acidic amino acids, aspartic and glutamic acids, on the increase of oxygen consumption by mitochonria is suggested. Cytotoxicity of the germinated seeds extract was tested by the assessment of the viability, the morphological changes and the proliferation of cell cultured human skin fibroblasts. It has been shown that germinated seeds extract are non-toxic to cell cultures at doses of up to 10 mg mL(-1); neither morphological changes nor membrane integrity alterations or changes in cell proliferation were observed.     

A review of ageing and an examination of clinical methods in the assessment of ageing skin. Part I: Cellular and molecular perspectives of skin ageing

The ageing process is noticeable within all organs of the body and manifests itself visibly in the skin. Skin ageing is influenced by several factors including genetics, environmental exposure, hormonal changes and metabolic processes. Together these factors lead to cumulative alterations of skin structure, function and appearance. The functioning of the central nervous, immune, endocrine and cardiovascular systems, as well as the skin is also impaired with age. Chronologically, aged skin is thin, relatively flattened, dry and unblemished, with some loss of elasticity and age-related loss of architectural regularity. General atrophy of the extracellular matrix is reflected by a decrease in the number of fibroblasts. Reduced levels of collagen and elastin, with impaired organization are primarily because of decreased protein synthesis affecting types I and III collagen in the dermis, with an increased breakdown of extracellular matrix proteins. Oxidative stress is considered of primary importance in driving the ageing process. The original free radical theory of ageing purported that the molecular basis of ageing was derived from a lifetime accumulation of oxidative damage to cells resulting from excess reactive oxygen species (ROS) produced as a consequence of aerobic metabolism. Although the skin possesses extremely efficient anti-oxidant activities, during ageing, ROS levels rise and anti-oxidant activities decline. The ROS are necessary in multiple MAP kinase pathways and the induction of AP-1, in turn, up-regulates expression of matrix-metalloproteinases providing a plausible mechanism for the increased collagen degradation in aged human skin.     

'Healthy skin': significance and results of an Italian study on healthy population with particular regard to 'sensitive' skin

There is an increasing demand in general population regarding skin healthiness and improvement of aesthetical appearance, indicating that people require more information about how to treat healthy skin and to prevent skin disease. This study is the result of a campaign on healthy skin organized by the International Society of Plastic Dermatology. This campaign was at the same time an occasion to perform an epidemiological study on Italian population and was conducted during only one month (March 2004) throughout Italy. In total, 462 dermatologists all over Italy joined the project. Study protocol and diagnostic kits were provided to all adhering dermatologists. After signing an informed consent, subjects were assigned to undergo anamnesis, medical examination and stinging test with 10% lactic acid at the level of nasolabial fold. A total of 2101 duly compiled case record forms were sent back by the dermatologists. The analysis of the demographic features and lifestyle of the subjects who were attracted by the campaign allows us to draw the identikit of people interested in the maintenance of a healthy skin, i.e. mainly young women, who already lead a healthy life and took care of their skin. Sensitive skin was common in this healthy population.     

Exposure to heterocyclic aromatic amines from the consumption of cooked red meat and its effect on human cancer risk: A review

This review covers the bibliographic data from the last 10 years on the possible carcinogenicity of heterocyclic aromatic amines (HAAs) in humans. Aspects such as red meat intake, cooking methods applied to red meat, and doneness of cooking are discussed from an epidemiological point of view. The role in the carcinogenicity of the HAAs has been assigned to two main factors: first, the very high frequency of consumption of red meat; and, second, very darkly browned meats from cooking. However, there are some uncertainties associated with epidemiological results such as the presence of other carcinogens, co-carcinogens and anti-carcinogens in the diet, analytical results on the content of HAAs in foods, food frequency questionnaires, and mainly genetic susceptibility to HAAs. It is concluded that there is not sufficient scientific evidence to support the hypothesis that human cancer risk is due specifically to the intake of HAAs in the diet.     

Prediction of thermal skin burn based on the combined mathematical model of the skin and clothing

As the result of exposed to thermal radiation and fire exposure, skin burn or even worse injuries are very common for building occupants and fire fighters. To accurately predict their skin temperature and burn situation, an assessment method of the mathematical model is developed for various thermal radiation conditions. The combined mathematical model includes the heat and moisture transfer within the skin and clothing systems. It is validated with a good agreement with the previous experimental study. The effects of thermal radiation, air gap and moisture transfer on burn prediction were also studied. The results showed that the time to the second degree burn is affected by the heat flux level, gap size and moisture location. It is expected that the developed method can be used to evaluate the thermal protective performance of protective clothing during exposure to thermal hazards and provide appropriate information to clinical observation and decision-making for skin thermal injuries.     

Instability of an aromatic amine in fatty food and fatty food simulant: characterisation of reaction products and prediction of their toxicity

It is a well-known fact that amines are not stable in food of a fatty nature. In this study the synthesis and characterisation of the products obtained as a result of the reaction of amines in a fatty medium are reported. Based on the well-known reactions among amines and acid and esters groups, two novel compounds were synthesised using m-xylylenediamine (mXDA), a primary diamine widely used as monomer in the manufacture of food contact materials and two fatty acids, oleic acid and palmitic acid, which occur in most fats. The resulting compounds were two molecules belonging to the family of fatty acid amides, dioleamide and dipalmitamide. A complete characterisation of both products was carried out employing several techniques such as infrared spectroscopy, ¹H- and ¹³C-NMR spectroscopy, electron ionisation mass spectrometry, LC-MS/MS and UV spectrometry. The results obtained by the different techniques were well correlated. In the second part of the work, the formation of these compounds in real samples was evaluated. For this purpose a certain volume of olive oil was spiked with a known amount of mXDA. Olive oil was selected as a fatty medium since it is a widely consumed food and additionally is used as a fatty food simulant in migration studies of food contact materials. A method was developed to extract the fatty acid amides from the fatty matrix, which were then identified by LC-MS/MS. The toxicity of the synthesised compounds was predicted using a toxicity estimation software tool.     

Survey on the occurrence of photo-initiators and amine synergists in cartonboard packaging on the German market and their migration into the packaged foodstuffs

In a surveillance study from 2008 to 2011, in total 310 food products, predominately packed in cartonboard, were collected from the German market. First, the packaging materials were analysed for their content of six photo-initiators and five amine synergists by high-performance liquid chromatography with diode array detection (HPLC-DAD). If high amounts of these substances were detected, subsequently the foodstuffs were analysed by means of HPLC-MS or tandem MS, respectively. Benzophenone (BP) was detected in 49% of the packaging materials and was thus the most often determined compound, followed by 4-methylbenzophenone (MBP, 8%), 1-hydroxy-cyclohexylphenylketone (HCHPK, 7%) and methyl-o-benzoylbenzoate (MOBB, 5%). In total, 99 foodstuffs were analysed and in 20 cases one or more photo-initiators and/or amine synergists were detected in quantities above the legally acceptable limits in food. This resulted in several notifications in the European Rapid Alert System for Food and Feed (RASFF); the best known is MBP in breakfast cereals. Contamination of the foodstuff by the photo-initiators and/or amine synergists also occurred when it was in indirect contact with the printed packaging material and no adequate barrier material was used to prevent migration. The data also clearly demonstrate that polyethylene films are not suitable to inhibit migration. Storage of samples until the best before date showed that HCHPK, BP and MBP migrate very easily via the gas phase. In contrast, 4-phenylbenzophenone and 4,4′-bis(diethylamino)benzophenone migrated only very slowly or, respectively, not in quantifiable amounts into the foodstuffs. Differences in transfer rates for HCHPK, BP and MBP from several packagings into food and Tenax^®, respectively, lead to the assumption that both the food matrix as well as the extent of cross-linking of the printing ink during curing may have an influence on the level of migration.     

Infant skin physiology and development during the first years of life: a review of recent findings based on in vivo studies

Infant skin is often presented as the cosmetic ideal for adults. However, compared to adult skin it seems to be more prone to develop certain pathological conditions, such as atopic dermatitis and irritant contact dermatitis. Therefore, understanding the physiology of healthy infant skin as a point of reference is of interest both from the cosmetic as well as from the clinical point of view. Clinical research on healthy infants is, however, limited because of ethical considerations of using invasive methods and therefore until recently data has been scarce. Technical innovations and the availability of non‐invasive in vivo techniques, such as evaporimetry, electrical impedance measurement, in vivo video and confocal microscopy, and in vivo fibre‐optic based spectroscopy, opened up the field of in vivo infant skin physiology research. Studies incorporating such methods have demonstrated that compared to adult, infant skin continues to develop during the first years of life. Specifically, infant skin appears to have thinner epidermis and stratum corneum (SC) as well as smaller corneocytes at least until the second year of life. The water‐handling properties are not fully developed before the end of the first year and infant SC contains more water and less amounts of natural moisturizing factors. Such findings re‐evaluate the old notions that skin is fully matured at birth. Armed with this knowledge, we are in a position not only to better understand infant dermatological conditions but also to design better skin care products respecting the distinct qualities of infant skin.     

A combined approach in characterization of an effective w/o hand cream: the influence of emollient on textural, sensorial and in vivo skin performance

To formulate a consumer-acceptable cosmetic product, numerous demands have to be fulfilled, and as the most important, efficacy (both real and perceived), adequate aesthetic (visual perception) and all sensorial characteristics have to be achieved. In this study, four model water-in-oil creams intended for hand care, varying in one emollient component, were submitted to rheological, sensory and textural characterization, and their efficacy was evaluated in in vivo study on human volunteers. Our results indicate that certain alteration restricted to the oil phase induced a change in all investigated characteristics, showing that each instrumental measurement can be used as a sensitive tool in the characterization of cream samples. Regarding the correlation between physical measurements and certain sensory attributes, it is possible to formulate a product with specific sensory characteristics by using pre-defined rheological or textural parameters. To obtain a complete sensory profile of a cosmetic product, a detailed sensory evaluation should be carried out according to the existing standard practices, which are both time- and money-consuming. However, a modified sensory study could be useful for fast in-line screening along with instrumental characterization of a novel cosmetic emulsion product and could be particularly helpful in the process of distinguishing a single formulation from several differing in one component.     

戊二醛交联壳聚糖树脂的性能表征及其吸附性能研究

文章以壳聚糖为原料,选用戊二醛为交联剂制备壳聚糖吸附树脂。从失重率、含水率、保水率、孔度值、电子扫描显微镜照片、红外光谱等方面对壳聚糖树脂进行了表征。并利用壳聚糖树脂处理吸附活性染料,研究废水的吸附性能,测试了树脂的再生吸附能力。结果表明,壳聚糖交联树脂和经脱吸再生后的树脂对印染废水具有良好的脱色能力,而且脱吸再生次数可达8次。     

Influence of topically applied ceramide/phospholipid mixture on the barrier function of intact skin, atopic skin and experimentally induced barrier damage

The influence of a liposomal formulation of a ceramide/phospholipid mixture on the barrier function of the skin in atopic tests, in subjects with healthy skin, and after lipid extraction was tested. The transepidermal water loss and the stratum corneum hydration served as parameters for the evaluation of the influence of the ceramide/phospholipid-mixture treatment on the barrier function. Additionally a barrier-function test with nicotinic acid ester was performed after ceramide/phospholipid-mixture application. Stabilizing effects on the barrier function after application of ceramide/phospholipid-mixture were found only in atopic skin and after lipid extraction but not in healthy skin. The results lead us to expect positive effects of ceramide/phospholipid-mixture only if barrier damage is present.     

Rheological and functional properties of gelatin from the skin of Bigeye snapper (Priacanthus hamrur) fish: Influence of gelatin on the gel-forming ability of fish mince

The rheological and functional properties of gelatin from the skin of bigeye snapper (Priacanthus hamrur) fish were assessed. The protein content of dried gelatin was 94.6% and moisture content was 4.2%. The amino acid profile of gelatin revealed high proportion of glycine and imino acids. The bloom strength of solidified gelatin was 108 g. The average molecular weight of fish skin gelatin was 282 kDa as determined by gel filtration technique. The emulsion capacity (EC) of gelatin at a concentration of 0.05% (w/v) was 1.91 ml oil/mg protein and with increase in concentration, the EC values decreased. The gelling and melting temperatures of gelatin were 10 and 16.8 °C, respectively as obtained by small deformation measurements. The flow behavior of gelatin solution as a function of concentration and temperature revealed non-Newtonian behavior with pseudoplastic phenomenon. The Casson and Herschel–Bulkley models were suitable to study the flow behavior. The yield stress was maximum at 10 °C with the concentration of 30 mg/ml. Thermal gelation behavior of threadfin bream (Nemipterus japonicus) mince in presence of different concentration of gelatin was assessed. Gelatin at a concentration of 0.5% yielded higher storage modulus (G′) value than control. Frequency sweep of heat set gel with gelatin revealed strong network formation.     

Optimization of the procedure for the determination of polycyclic aromatic hydrocarbons and their derivatives in fish tissue: Estimation of measurements uncertainty

Three alternative procedures were employed for the isolation of polycyclic aromatic hydrocarbons (PAHs; 15 of 16 US EPA priority pollutants and benzo[e]pyrene), their methyl-derivatives and sulphur analogues from fish tissue: (1) Soxhlet extraction, (2) batch extraction enhanced by sonication, and (3) saponification of the sample followed by re-extraction of analytes into hexane. Soxhlet extraction using hexane-acetone (1:1, v/v) was the most efficient extraction technique, with analyte recoveries in the range 70-108%. Within optimization of the clean-up step, several types of gel permeation chromatography (GPC) systems were tested: two types of polystyrene divinylbenzene copolymer gels (PSDVB), both 'soft' gel type (Bio-Beads S-X3) and 'rigid' gels type (PL gel and Envirogel) in combination with various mobile phases were compared. Bio-Beads S-X3 and mobile phase chloroform were the most appropriate for purifying of crude extracts before the final determinative step. High-performance liquid chromatography with fluorimetric detection (HPLC/FLD) was used for identification and quantification of PAHs in purified fish extracts. The uncertainties of PAHs measurements were estimated by employing two alternative approaches. Both provided similar results: the expanded uncertainties obtained for individual PAHs by the 'top-down' approach were in the range 9-53%, their values resulting from application of the 'bottom-up' approach were in the range 16-52%.     

Effect of low temperatures on the rate of respiration and uptake of phosphine in different life stages of the cigarette beetle Lasioderma serricorne (F.)

Studies were undertaken to establish the effects of low temperatures on the rate of respiration in larvae and adults of a susceptible strain of the cigarette beetle Lasioderma serricorne. The results showed that there was a consistent decrease in the rate of respiration in L. serricorne with a decrease in temperature from 25°C to 5°C. The rate of respiration was slightly affected by circadian rhythm in adult beetles, but not in larvae.The levels of phosphine taken up by different life stages of the beetle were also determined using [³²P]-radiolabelled gas. A comparison between susceptible and phosphine resistant strains showed that the mechanism of resistance in L. serricorne involves a reduced uptake of the fumigant.The uptake of [³²P]-phosphine by different life stages of resistant L. serricorne declined with a decrease in temperature from 25°C to 5°C. Similarly, the uptake by susceptible L. serricorne decreased from 25°C to 10°C, but there was a comparatively higher uptake at 5°C and consequently a higher mortality at the end of the exposure. The significance of the findings in relation to control strategies is discussed.     

红衣组分对花生分离蛋白及其酶解产物理化和抗氧化性质的影响

以花生为原料,研究了花生红衣组分对花生分离蛋白及其酶解产物理化和抗氧化性质的影响。研究结果表明:含红衣的分离蛋白酶解速度低于不含红衣的;相同水解度条件下,含红衣的表面疏水性小于脱红衣的;GPC分布中,含红衣的峰值大于脱红衣的;红衣组分能够提高花生分离蛋白及其酶解产物的溶解性、乳化稳定性、乳化活性;在相同水解度条件下,含红衣的水解产物多酚含量显著高于脱红衣的,多酚含量的差异与花生分离蛋白及其水解产物的抗氧化性具有正相关性。     

Biochemical effects of unsaponifiable lipidic components of avocado and soya bean administered percutaneously on the connective tissue components of hairless rat skin

The unsaponifiable lipidic fractions of avocado and soya bean were administered percutaneously, on the dorsal skin of hairless rats for 15 days, in a 5% sweet almond oil solution. This treatment produced a modification of dermal connective tissue components. The biochemical analysis showed an increase of soluble proteins, especially of salt soluble collagen together with a decrease of proteins insoluble in neutral buffer. The ratio, soluble proteins:insoluble proteins, increases as well as the ratio soluble collagen: insoluble collagen. These modifications can be considered as a result of the activation of connective tissue metabolism. The above results are in agreement with those obtained when the unsaponifiables were administered per os to rats. Effets biochimiques, sur le tissu conjonctif sous cutané des insaponifiables de soja et d'avocat adminstrés par voie percutanée chez le rat sans poils