Volatile flavor release from foods during eating

Classical analyses for volatile flavors (headspace or distillation/extract methods) give information on either the volatiles present in the air above a food before eating or the total volatile composition of the food. When foods are eaten, however, many changes take place (such as hydration/dilution with saliva, increase in surface area, etc.) that affect the release of volatiles from the food and therefore the profile of volatiles that are sensed in the nose. If we wish to study the relationship between flavor volatiles and the sensory properties of a food, it seems logical to measure the volatile profile that exists during eating. Although volatile flavor release during eating has been measured using a variety of sensory and psychophysiological analyses, only recently have instrumental methods been developed to measure the release of volatile compounds in humans as they eat. Whereas the sensory data give an overall measure of flavor perception, instrumental analyses can potentially follow the release of each and every flavor volatile and thus give a full picture of the aroma profiles generated during eating. From these instrumental measurements, a number of key factors have been identified. First, it has been shown that the volatile profile measured during eating is indeed different from the headspace profile of whole foods. Second, it is clear that the volatile profile in‐mouth changes with time as the state of the food changes with chewing. Third, the volatile release from low‐water foods is affected by the rate and extent of hydration in‐mouth. The ability to measure aroma before, during, and after eating may lead to an understanding of the links between aroma release, interaction of volatiles with aroma sensors in the nose, and the overall perception of food flavor.     

Food aroma mass transport properties in renewable hydrophilic polymers

The sorption and transport properties of gliadin and chitosan films with respect to four representative food aroma components (ethyl caproate, 1-hexanol, 2-nonanone and α-pinene) have been studied under dry and wet environmental conditions. The partition coefficients (K) of the selected volatiles were also obtained using isooctane and soybean oil as fatty food simulants. The results showed that gliadin and chitosan films have very low capacities for the sorption of volatile compounds, and these capacities are influenced by the nature of the sorbate, the environmental relative humidity and the presence of glycerol as a plasticizer in the polymeric matrix. The volatile compounds also present a low partitioning in the biopolymer film/food stimulant system. Given the low levels of interaction observed with the volatiles, gliadin and chitosan films are of potential interest for the packaging of foods in which aroma is one of the most important quality attributes.     

Release of Allyl Isothiocyanate from Mustard Seed Meal Powder

Allyl isothiocyanate (AITC) is a wide‐spectrum antimicrobial compound found in mustard seeds, produced when their tissues are disrupted. The formation of AITC in mustard seed is mediated by the myrosinase enzyme which catalyzes the release of volatile AITC from a glucosinolate—sinigrin. Since water is a substrate in the reaction, humidity from the air can be used to activate the release of AITC from mustard seed. In this study, defatted and partially defatted mustard seed meals were ground into powders with particle size ranging from 5 to 300 μm. The mustard seed meal powder (MSMP) samples were enclosed within hermetically sealed glass jars wherein the headspace air was adjusted to 85% or 100% relative humidity at 5, 20, or 35 °C. Data from gas chromatography analysis showed that AITC release rate and amount increased with increasing relative humidity and temperature. Moreover, the release rate can be manipulated by particle size and lipid content of the MSMP samples. The amount of AITC released ranged from 2 to 17 mg/g MSMP within 24 h under the experimental conditions tested. In view of the antimicrobial properties of AITC, the mustard meal powder may be used as a natural antimicrobial material for extending the shelf life of food products.     

Prediction of Equilibrium Moisture Content of Various Foods Using a Neural Network

A neural network was developed for learning the isotherm data and determined the relationship of equilibrium moisture content and relative humidity at various temperatures and for different food products. Data were taken from the literature for 53 food products. Neural network inputs were temperature, relative humidity or water activity, and food product number (1–53) or six binary elements (000001 to 110101) to express these food products. Food product input in binary numbers provided much better accuracy than using numerical numbers. The optimum neural network structure was three middle layers with 30 nodes in each layer with 0.9 values of both learning rate and momentum. The mean relative error was only 2%.     

Influence of factors on release of antimicrobials from antimicrobial packaging materials

Antimicrobial packaging materials (films or coatings) (APMs) have aroused great interest among the scientists or the experts specialized in material science, food science, packaging engineering, biology and chemistry. APMs have been used to package the food, such as dairy products, poultry, meat (e.g., beef), salmon muscle, pastry dough, fresh pasta, bakery products, fruits, vegetables and beverages. Some materials have been already commercialized. The ability of APMs to extend the shelf-life of the food depends on the release rate of the antimicrobials (AMs) from the materials to the food. The optimum rate is defined as target release rate (TRR). To achieve TRR, the influencing factors of the release rate should be considered. Herein we reviewed for the first time these factors and their influence on the release. These factors mainly include the AMs, food (or food simulant), packaging materials, the interactions among them, the temperature and environmental relative humidity (RH).     

Effect of relative humidity on the migration of benzophenone from paperboard into the food simulant Tenax® and modelling hereof

The aim of this study was to investigate the effect of relative humidity on the migration of benzophenone from paperboard into the food simulant Tenax®. Kinetic migration investigations were carried out with three relative humidities in the interval between 39% and >73%. All investigations were carried out at a constant temperature of 34°C. It was found that the migration of benzophenone after more than 30 days was 4.8 times higher at a relative humidity of 64%–71%, and 7.3 times higher at a relative humidity of >73%, compared with that at a relative humidity of 39%–49%. Diffusion and partition coefficients were derived from the results by using a software for modelling migration in multilayer materials. Both the diffusion coefficient and the partition coefficient, between paperboard and Tenax®, decrease with increasing relative humidity. The experimental results were correctly modelled only when the paperboard was regarded as a one-layer system as compared with a two-layer system: where the main part of the paperboard (B1) has a high diffusion rate and a thin part of the paperboard (B2) in contact with the foodstuff has a lower diffusion rate.     

Optimizing the use of garlic oil as antimicrobial agent on fresh-cut tomato through a controlled release system

Encapsulation of garlic oil (GO) in β-cyclodextrin (β-CD) was undertaken to generate a release system of antimicrobial volatiles and tested on microbial growth and sensory quality of fresh-cut tomato. GO volatile profile was characterized by gas chromatography mass spectrometry and to demonstrate the disadvantages of applying free GO to fresh-cut tomato, the effect of different free oil treatments (0, 50, 100, and 200 μg/100 g) on microbial growth and sensorial quality was tested. The effect of GO capsules (0, 0.25, 0.5, and 1 g/100 g) on microbial growth and sensory quality of tomato was also investigated. Allyl disulfide was the most abundant GO compound identified. The release of volatiles from GO: β-CD capsules (12: 88 [w/w] ratio) was evaluated at 100% relative humidity (RH). Close to 70% of GO volatiles were released from capsules when exposed to 100% RH during 5 wk. The most effective antimicrobial concentrations of free oil (100 and 200 μg/100 g) applied to tomatoes did not present acceptable sensory quality for panelists. Tomato was affected by the highest concentration of GO capsules applied, showing the lowest microbial growth and the highest sensory quality. In this context, successful encapsulation in β-CD could stimulate further interest in the use of GO for the control of microbial growth in fresh-cut tomato. PRACTICAL APPLICATION: The present study demonstrated that relative humidity in-package of fresh-cut tomatoes can be used as a trigger to release antimicrobial garlic oil volatiles from β-cyclodextrin capsules, reducing microbial growth and the sensory effect of the treatment caused by the free garlic oil. In this context, successful encapsulation in β-cyclodextrin could stimulate further interest in the use of garlic oil for the control of microbial growth in fresh-cut tomatoes.     

藜蒿黄酮微胶囊工艺优化及释放动力学研究

为探究藜蒿黄酮微胶囊最佳制备工艺及其释放性能,采用分子包埋法以藜蒿黄酮为芯材、β-环糊精为壁材制备藜蒿黄酮微胶囊并通过单因素及响应曲面法优化微胶囊制备工艺;通过测定微胶囊在不同温度和相对湿度下的黄酮保留率,并引用Avrami's方程对各条件下微胶囊的释放动力学进行拟合,并对其释放速率常数与释放机理参数进行分析.结果表明...     

Mathematical model to describe the release of an antimicrobial agent from an active package constituted by carvacrol in a hydrophilic EVOH coating on a PP film

Antimicrobial active packaging is a novel technology in which a chemical compound (or mixture) is purposely incorporated into a packaging material to be released into the food to protect it from deterioration. The effectiveness of an antimicrobial package is strongly related to the balance between the controlled release of the active compound and microbial growth kinetics. This work characterizes and models the release of carvacrol from an EVOH coating on a PP film which can be employed as an active packaging system. The kinetics and extent of carvacrol mass transport within the packaging components were fully characterized as a function of relative humidity. As expected, water uptake by the EVOH coating acts as a triggering mechanism for activity. The partition equilibrium for carvacrol in the complex film largely favors (10,000-fold) the EVOH layer in dry conditions, although in humid conditions the solubility in both polymers is very close (4-fold). Kinetically, the presence of humidity increases the value of D for carvacrol in EVOH from 3 · 10⁻¹⁹ m²/s in dry conditions to 3 · 10⁻¹⁵ m²/s in a wet environment.After the experimental characterization of carvacrol transport, the efficiency of the release of carvacrol was estimated with a novel mathematical model based on the finite element method and successfully compared with the evolution of carvacrol concentration in a real packaging system. The model developed can be employed in the optimization of package design in order to ensure the maintenance of a specific concentration of the active agent in the headspace, high enough to prevent potential growth of a particular foodborne spoiling or pathogenic microorganism on the preserved foodstuffs. This model could easily be extended to similar packaging systems as long as an inventory of experimental data for all the parameters and coefficients involved is available, sufficiently complete to fulfill all the mathematical requirements demanded by the model.     

Changes in flavour release from rehydrated: Diced bell peppers (Capsicum annuum) by artificial saliva components in three mouth model systems

The effect of artificial saliva components on flavour release from dehydrated diced red bell peppers (Capsicum annuum) was studied in a mouth model system. This measured the dynamic headspace under oral conditions, such as temperature, volume of the mouth, salivation, and mastication (DHM). The results were compared with a dynamic headspace (DH) and a purge-and-trap (PT) model system. Volatile compounds were analysed by gas chromatography, using flame ionisation detection (FID), mass spectrometry (MS), and sniffing port detection (SPD). SPD revealed that only 12 of the 47 compounds identified by MS and FID possessed odour activity. For all saliva compositions FID peak areas of volatile compounds were largest in the PT system, followed by DHM and DH, respectively. In the PT system the less volatile compounds were relatively better released than other volatile compounds in comparison with the DHM and DH system, for all salivas. The saliva components mucin and α-amylase caused a relative decrease in release of the less volatile compounds in all model systems. An overall decrease in FID peak areas of volatile compounds by the latter components was observed in model system DH only.     

Characterization of hydrophobic hypercrosslinked polymer as an adsorbent for removal of chlorinated volatile organic compounds

A hydrophobic hypercrosslinked polymer with poly (4-tert-butylstyrene-styrene-divinylbenzene) matrix (LC-1) was prepared as adsorbent for the removal of volatile organic compounds from gas streams. The content of oxygen-containing functional groups of LC-1 was about one-fourth that of commercial hypercrosslinked polymeric adsorbent (NDA-201). The results of the water vapor adsorption experiment indicated that LC-1 had a more hydrophobic surface than NDA-201. Three chlorinated volatile organic compounds (trichloroethylene, trichloromethane, and 1, 2-dichloroethane) were used to investigate the adsorption characteristics of LC-1 under dry and humid conditions. Equilibrium adsorption data in dry streams showed that LC-1 had good adsorption abilities for three chlorinated VOCs due to its abundant micropore structure. Moreover, the presence of water vapor in the gas stream had negligible effect on breakthrough time of three chlorinated VOCs adsorption onto LC-1 when values of relative humidity were equal to or below 50%; the breakthrough time of three chlorinated VOCs decreased less than 11% even if the relative humidity was 90%. Taken together, it is expected that LC-1 would be a promising adsorbent for the removal of VOCs vapor from the humid gas streams.     

超声辅助溶剂萃取结合气相色谱-质谱法分析自热食品聚丙烯包装中挥发性成分

对超声辅助溶剂萃取法的萃取时间进行优化;在最佳萃取条件下,建立超声萃取结合气相色谱-质谱测定3 种自热食品聚丙烯包装的挥发性成分的方法;对比正己烷、乙醇、乙酸乙酯和二氯甲烷4 种溶剂的萃取效果,通过MS-DIAL解卷积、NIST谱库检索结合色谱保留指数对检出物质定性,利用毒理学关注阈值法确定其Cramer分类等级,并计算相对气味活度值分析潜在气味物质。结果表明：正己烷、乙酸乙酯、二氯甲烷的萃取效果相近,均对烃类物质有较好的提取效果;而乙醇对酯类物质的提取效果较好。3 种自热食品聚丙烯包装样品中共检测出72 种挥发性成分,其中N-(2-乙氨基)-1,3-丙二胺、壬醛、2,4-二叔丁基酚、2,6-二叔丁基对甲酚等12 种成分需引起关注。通过查阅资料,共确定14 种挥发性气味物质,其中壬醛、正十一烷和正十六烷等可能对自热食品聚丙烯包装的气味有潜在贡献。本研究为自热食品聚丙烯包装挥发性成分的分析提供一定的方法依据,并为自热食品聚丙烯包装的安全性评估和气味分析提供数据支持。     

金属氧化膜传感器在食品风味和质量中的应用研究

研究以食品风味为内容的分类分析和质量鉴别。应用多元组合型金属氧化膜感测器FOX3000 Electronic NoseSystem对59种茶叶、5种咖啡等嗜好性饮料进行“非破坏性”检测,将获得的感测数据应用主成分分析和判别分析方法进行茶叶样品分类识别,5种咖啡采用湿度和温度不同贮藏处理后再经检测,对其品质质量变化对比分析。分析结果显示不仅可以进行茶业类别区分,也可以区分产地、贮藏条件等与茶叶、咖啡质量有关联的品质影响因素。金属氧化膜传感器除在应用于食品风味类型的识别,还能够进一步推广应用于具有风味表现的食品质量鉴别与识别。     

Overview of RFID Technology and Its Applications in the Food Industry

ABSTRACT:  Radio frequency identification (RFID) is an alternative technology with a potential to replace traditional universal product code (UPC) barcodes. RFID enables identification of an object from a distance without requiring a line of sight. RFID tags can also incorporate additional data such as details of product and manufacturer and can transmit measured environmental factors such as temperature and relative humidity. This article presents key concepts and terminology related to RFID technology and its applications in the food industry. Components and working principles of an RFID system are described. Numerous applications of RFID technology in the food industry (supply chain management, temperature monitoring of foods, and ensuring food safety) are discussed. Challenges in implementation of RFID technology are also discussed in terms of read range, read accuracy, nonuniform standards, cost, recycling issues, privacy, and security concerns.     

Inclusion complexes dispersed in polystyrene‐based labels for fruit ripening on demand

In this work, the inclusion complexes of α‐cyclodextrin and ethylene were prepared by molecular encapsulation and then dispersed into a polystyrene film by solvent casting to produce active polymeric labels. These labels were produced to control ripening of fruit directly in the food container as an alternative to the injection of ethylene into thermo‐regulated chambers. The samples were characterised, and the ethylene release was found to be dependent on temperature and relative humidity in the atmosphere. Finally, experimental data were used to simulate a realistic scenario of fruit ripening into a food container, showing the possibility to trigger ripening with the active label within 2 days. Polystyrene/inclusion complex labels showed in situ release of ethylene, potentially able to trigger ripening of fruit in a food container within desired time, reducing costs in the supply chain and postharvest losses.     

丹尼斯克北京菌种工厂获得食品和保健食品生产许可

<正> 2010年8月,丹尼斯克北京菌种工厂取得了北京质量监督局颁发的固体饮料生产许可证(QS112406010428)、北京市药监局颁发的益生菌固体饮料保健食品生产许可证((京药)卫食证字(2010)110000-JS0022)以及符合《保健食品良好生产规范》的证明函(京药监保证2010006)。这是全球益生菌顶级供应商在亚太区唯一具有生产普通食品和保健食品的资质和配套设施的工厂。     

异硫氰酸烯丙酯的分子包埋物在不同温度下的控制释放

本论文利用β-环糊精对异硫氰酸烯丙酯进行分子包埋,将液态油转变为固体的包合物粉末,同时对其释放特性进行研究。结果表明,异硫氰酸烯丙酯可以和β-环糊精形成包合物,包合物中异硫氰酸烯丙酯的释放速度与环境的相对湿度密切相关,释放过程可以用Avrami方程进行较好的拟和。环糊精的包埋释放反应是一个动态的可逆过程,在密闭体系中存在一个异硫氰酸烯丙酯的顶空平衡浓度。     

Real-Time Detection of Volatiles Released During Meat Spoilage: a Case Study of Modified Atmosphere-Packaged Chicken Breast Fillets Inoculated with <Emphasis Type="Italic">Br. thermosphacta</Emphasis>

The microbial spoilage of meat is accompanied by the release of volatile organic compounds (VOCs), many of which are odorous. These compounds give spoiled meat its characteristic pungent, sour, sulphury odour that provides consumers with an indication that the meat is unpalatable. Characterising meat spoilage based on volatile markers is of interest to the food industry in view of developing food freshness indicators (FFIs) to maintain food quality and reduce food waste. Conventional analytical methods for detecting VOCs developing during food spoilage involve intermittent sampling that delivers only snapshots of the release processes and thereby only limited information on the kinetics of their production and release. Proton-transfer-reaction mass spectrometry (PTR-MS) is an on-line technique that enables the detection of VOCs in real-time, thereby offering the possibility to follow the release of VOCs with a high time resolution. An analytical method using PTR-MS was developed to enable the continuous detection of VOCs released from chicken breast fillets inoculated with Brochothrix thermosphacta and stored under modified atmosphere (30 % CO₂, 70 % O₂) at 4 °C for 1 week. The meat spoilage VOCs detected by PTR-MS displayed different temporal dynamics of production and release, depending on the extent of spoilage. This paper describes the development of an analytical set-up for real-time detection of volatile spoilage markers using PTR-MS. This case study using inoculated chicken breast fillets demonstrates the applicability of this method to characterise individual VOC release patterns, which is of potential utility in the development of FFIs for the consumer market.     

Effect of thermal processing and storage condition on the flavour stability of spray-dried durian powder

Stability of key odour volatiles (propanethiol, ethyl propanoate, ethyl 2-methylbutanoate and diethyl disulfide) from spray-dried durian powder that was subjected to accelerated storage were analysed quantitatively using headspace solid phase microextraction coupled to fast gas chromatography-mass spectrometry. The type of drying aids incorporated significantly influenced volatiles retention in the powder product. The addition of gum Arabic resulted in higher retention of volatiles in the durian powder as compared to maltodextrin and N-Lok starches. Volatiles that remained in the powder ranged from 57% to 76% of the original concentration. Volatile composition of the powder product was altered with only two aldehydes included 2- and 3-methyl butanal and no off-flavour volatile was detected throughout the storage. The rates of volatiles release from the spray-dried powder under accelerated storage condition increased markedly at higher relative humidity.     

A method to mimic and to study the release of flavour compounds from chewed food

A method for analysing the flavour release from chewed food has been developed. Flavour release is studied in an artificial mouth simulating the process of chewing and using fluid model systems, in our case aromatised oil in water emulsions. The fast transfer of volatile substances from the chewpulp into the gaseous phase is followed up by comparing six quickly taken gas samples. Volatile substances are analysed by means of a special technique which includes cryofocusing and capillary gas chromatography. As a wide spectrum of individual volatile substances is considered, systematic investigations into the flavour release from food under mouth-typical conditions are possible.