Mass transport analysis in perforation-mediated modified atmosphere packaging of strawberries

A space-and-time dependent mathematical model was developed to predict O₂, CO₂, N₂ and H₂O concentration in perforation-mediated polymeric packages during cold-storage of strawberries. The numerical solution of the corresponding mathematical model was obtained by applying the finite element method (FEM). The problem was solved in a domain corresponding to the headspace of a package augmented by the total void spaces of the contained bulk produce and for realistic boundary conditions. Transport of O₂, CO₂, N₂ and H₂O was modelled based on Maxwell–Stefan equations for gas transport through packaging’s headspace and on Fick’s law for diffusion through the micro-perforated packaging. The model predictions were tested against published experimental data of O₂ and CO₂ concentrations in modified atmosphere packaging storage of strawberries and the agreement is satisfactory. As for reaching the recommended in the literature gases concentrations for strawberry storage, the model predictions revealed that the tested micro-perforated polypropylene packaging combined with the adopted storage conditions are marginally adequate. To this end, the theoretical findings are suggestive of improvements, in terms of material properties, especially with regard to the permeability of the polymeric packaging film.     

Use of infrared analysis to identify genetic resources from isolated producers in Brazil as a tool to improve cassava competitiveness in the starch market

Our objective was to verify the potential of identifying different starches in Brazilian landraces of cassava using near and medium infrared analyses. The survey was conducted on 132 landraces collected throughout the Cerrado, Pantanal and Amazon biomes, in the Brazilian state of Mato Grosso, including 10 commercial starches. The results are reflective of selection for different genetic variants in small isolated producers. Infrared analysis enables rapid identification of this material and is the first step in identifying starches with different properties. The results demonstrate the potential of MIR analyses for in situ evaluation, an additional option for identifying important varieties and value the development of efforts made by small producers, whose landraces have special and economically important properties.     

Inter-Laboratory study to define the temperature interval for a thermoluminescence heating unit used to identify irradiated food

EN 1788:2001 suggests defining the temperature range for the thermoluminescence (TL) heating unit to calculate the TL ratio (TL₁/TL₂). In the present study, practical temperature ranges were established by using well-characterized lithium fluoride (LiF, TLD-100®) at 4 different research institutes in Korea. Temperature ranges differed according to models of TLD heating unit, which were wide in the case of RISØ (160–249°C) as compared with Harshaw (155–232°C) TLD readers. The silicate minerals separated from irradiated turmeric samples were measured to check these intervals on a practical basis. The X-ray diffraction (XRD) analysis of separated minerals showed that quartz and feldspar minerals were the main source of well-characterized TL glow curve following irradiation. The TL glow peaks from the separated minerals were narrower in Harshaw than RISØ TLD readers. The TL ratios determined after re-irradiation (1 kGy) for the tested minerals, using the pre-defined temperature intervals, provided the satisfactory results.     

2-Dodecylcyclobutanone as an irradiation dose indicator to identify and estimate original dose in irradiated ground beef

2-Dodecylcyclobutanone (2-DCB), as a chemical marker of irradiated lipid-containing foods, was used to detect whether ground beef patties were irradiated and to estimate the original absorbed dose. The ground beef patties (70/30) were irradiated at five targeted absorbed doses of 0.5, 1.0, 3.0, 5.0, and 7.0?kGy and stored for 0, 7, 14, 21, and 28?days, respectively at 4?°C. A rapid analytical method based on direct solvent extraction (DSE)/gas chromatography–mass spectrometry (GC–MS) was developed to analyze 2-DCB in γ-ray irradiated ground beef patties. The samples were extracted with acetonitrile via DSE using a tissue-mashing instrument, and then purified with a 1-g silica cartridge and analyzed via GC–MS. The results indicate a linear relationship between irradiation dose and the amount of 2-DCB produced in the irradiated samples (y?=?0.0608x–0.0004, R2?=?0.9899). In addition, a linear relationship was observed between the loss (%) of 2-DCB and storage time (L?=?1.958d–1.6596, R2?=?0.9597). Thus, a method for estimating the initial dose of irradiated food was developed based on these two line equations; this method explored the establishment of a determination model of the original irradiation dose of lipid-containing foods. The method was used to successfully estimate 2–7?kGy irradiated beef samples within 28?days with minimal deviation within ±15?%.     

Image analysis as a tool for measuring biological phenomena of the skin

In an industry very much concerned with image it is not surprising to find that Image Analysers are beginning to fulfil the potential that a few groups recognized some time ago. This presentation will outline briefly the principles of image analysis and demonstrate how these can be put to use in measurement. Skin will be referenced as the example almost throughout this text, though it is important to remember that there are other applications which may interest cosmetic chemists; in the field of particulates and emulsions for example, and generally in production quality control. Finally, since the technology is often very easy to use, potential dangers in its misuse will also be pointed out where necessary.     

Numerical simulation tool for wooden boards with a physically based approach to identify structural failure

Knots and the resulting fiber deviations are the main influencing parameters of the effective stiffness and strength behavior of wooden boards on a structural scale. Depending on the size, shape and arrangement of knots/knot groups, certain effective mechanical properties can remain unaffected or change significantly. For this reason, a reliable prediction of the mechanical behavior of wooden boards is a basic requirement for efficiently designed wood products and timber structures. Within this work, a Finite-Element simulation tool was developed, which is able to consider a realistic three-dimensional fiber course in the vicinity of knots and also accounts for density and moisture dependent strength and stiffness properties. The estimation of effective strength values within this tool is done by examining the qualitative stress changes in predefined volumes, and is based on the formation of failure zones predominantly caused by perpendicular-to-grain tension in the vicinity of knots. Comprehensive test series, comprising tensile and four-point bending tests were carried out and used for validation. In general, a very good correlation between numerical and experimental results was obtained.     

Development of antimicrobial polyolefin films containing lauroyl arginate and their use in the packaging of strawberries

Low-density polyethylene (LDPE) films were supplemented with lauroyl arginate ethyl (LAE) and characterized for physical, mechanical and antimicrobial properties as well as their use for fresh ‘Sulhyang’ strawberries packaging. LAE powder was added into the LDPE films at 0, 1, 3, 5, and 10% (w/w) and assessed for physical properties, gas permeation, thickness and color values. The results showed that incorporation of LAE into the LDPE matrix did not affect film thickness and color. The thermal stability of the LAE/LDPE film decreased with increasing concentrations of LAE. The LAE/LDPE film exhibited a rough surface and compact structure. Tensile strength were affected by addition of LAE on the other hand value of elongation at break were increased. The LAE/LDPE containing 5 and 10% LAE showed significant antimicrobial properties against mycelium growth. Further, 5 and 10% LAE/LDPE films were used for storage study and it showed that incorporation of LAE into LDPE film was an effective method for maintaining the quality of strawberries. Films containing LAE were very effective at reducing the total weight loss, maintaining firmness, and reduced fungal decay compared to the control strawberries at 10?°C. These results suggest that LAE/LDPE films are potential candidates for advanced packaging materials for the fruits packaging application.     

High Performance Index as a tool to identify the best combination of pearled fractions and durum wheat genotypes for semolina and pasta colour improvement

Debranning was applied to six durum wheat genotypes to identify specific fractions rich in carotenoids and lower in enzymatic activities useful for improving pasta colour. Six sequential debranning steps, each of 30 s, were applied. β-carotene, lutein, α-tocopherol and ash content and hydroperoxidation and bleaching activities of lipoxygenase were determined in all pearled fractions. A wide variability among the genotypes regarding the level of all components has been found. Most of the parameters were higher in the pearled fraction at 30 s than wholemeal. Compared to the latter fraction, a significant decreasing trend for both lipoxygenase activities and α-tocopherol and ash content was subsequently observed, while β-carotene decreased more slightly. Lutein content remained quite stable in all subsequent pearled fractions. The pearled fraction of the Ofanto obtained at 90 s of debranning was identified as the best genotype/pearled fraction combination through our High Performance Index tool.     

1,2-Propanediol in strawberries and its role as a flavour precursor

1,2-Propanediol has been identified in strawberries after solvent extraction, derivatisation to 1,2-bis(trimethylsily)oxypropane and analysis of its TMS derivative using GLC-MS and GLC-FID. The level of 1,2-propanediol in strawberries was fond to be 0.5 μg g⁻¹ of fresh weight of fruit. Thirty-nine per cent of added 1,2-propanediol was recovered from strawberries. When exogenous 1,2-propanediol was fed to strawberry callus cultures, 2,5-dimethyl-4-hydroxy-2H-furan-3-one-glucoside, the glucosylated form of one of the character-impact compounds of strawberry flavour, was formed.     

Development of a new modelling tool (FACET) to assess exposure to chemical migrants from food packaging

The approach used to obtain European Union-wide data on the usage and concentration of substances in different food packaging materials is described. Statistics were collected on pack sizes and market shares for the different materials used to package different food groups. The packaging materials covered were plastics (both flexible and rigid), metal containers, light metal packaging, paper and board, as well as the adhesives and inks used on them. An explanation as to how these data are linked in various ways in the FACET exposure modelling tool is given as well as an overview of the software along with examples of the intermediate tables of data. The example of bisphenol A (BPA), used in resins that may be incorporated into some coatings for canned foodstuffs, is used to illustrate how the data in FACET are combined to produce concentration distributions. Such concentration distributions are then linked probabilistically to the amounts of each food item consumed, as recorded in national food consumption survey diaries, in order to estimate exposure to packaging migrants. Estimates of exposure are at the level of the individual consumer and thus can be expressed for various percentiles of different populations and subpopulations covered by the national dietary surveys.     

Halophilic hydrolases as a new tool for the biotechnological industries

Halophilic micro‐organisms are able to survive in high salt concentrations because they have developed diverse biochemical, structural and physiological modifications, allowing the catalytic synthesis of proteins with interesting physicochemical and structural properties. The main characteristic of halophilic enzymes that allows them to be considered as a novel alternative for use in the biotechnological industries is their polyextremophilicity, i.e. they have the capacity to be thermostable, tolerate a wide range of pH, withstand denaturation and tolerate high salt concentrations. However, there have been relatively few studies on halophilic enzymes, with some being based on their isolation and others on their characterisation. These enzymes are scarcely researched because attention has been focused on other extremophile micro‐organisms. Only a few industrial applications of halophilic enzymes, principally in the fermented food, textile, pharmaceutical and leather industries, have been reported. However, it is important to investigate applications of these enzymes in more biotechnological processes at both the chemical and the molecular level. This review discusses the modifications of these enzymes, their industrial applications and research perspectives in different biotechnological areas. Copyright © 2012 Society of Chemical Industry     

Time-intensity as a tool for the measurement of meat tenderness

In the texture analysis of meat, tenderness is an attribute that changes over time from the initial bite to the residual phase before swallowing. In this study, continuous time-intensity measurements were recorded on a line scale and compared to a single time-averaged measurement. Thirty gluteobiceps gilt roasts representing two breeds and cooked at three oven temperatures were evaluated by eight trained assessors. Cores, taken both perpendicular and parallel to the muscle fibre, and slices were sampled from each roast. Assessors recorded their perception of tenderness continuously from initial bite to swallowing by moving a cursor on a computer screen (time-intensity) and over a chew count of eight (time-averaged). Results based on parameters summarizing the time-intensity curves were comparable to those of the time-averaged data. The time-intensity curves clearly illustrated the temporal features of the perception of tenderness.     

Introduction of primary antioxidant activity to chitosan for application as a multifunctional food packaging material

The objective of this study was to improve functionality of chitosan films by introducing the primary antioxidant property to chitosan molecule. Grafting of gallic acid (GA) on chitosan was most efficient when chitosan, GA, carbodiimide, and N-hydroxysuccinimide were used in the ratio 2·10⁻⁴:1:0.05:0.05. There was no significant difference in grafting efficiency when the reaction lasted 6 or 24 h. Chitosan with 80% degree of deacetylation (DDA) was efficiently grafted and increase in DDA did not improve grafting. Non-grafted, native chitosan had insignificant 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging ability (9.4%) and no reducing power. The GA-grafted chitosan had 34.26 mg GA/g, DPPH scavenging ability of 89.5%, reducing power of A₇₀₀ = 0.51, and was soluble in aqueous acetic acid. During storage of ground peanuts under stress conditions (50 °C, 20–30% RH), both chitosan and GA-chitosan pouches provided significant reduction in oxidation reactions. Furthermore, the GA-grafted chitosan reduced level of thiobarbituric acid reactive substances (TBARS), peroxide, and conjugated trienes formation as compared to polyethylene bags. GA-grafted chitosan shows promise as a candidate for multifunctional food packaging material.     

Application of ESR spectroscopy to identify and estimate original dose in irradiated cumin and white pepper

Feature changes in the ESR spectrum and the relationship between ESR intensity and irradiation dose ranging between 0 and 15.0 kGy were studied to detect irradiated cumin and white pepper by ESR spectroscopy. The absorbed irradiation doses of two samples were assessed using the dose-additive method. The ESR signal intensities of irradiated cumin and white pepper increased with increasing absorbed radiation dose. Even after 220 days, the ESR method could still be used to identify whether or not cumin and white pepper had been irradiated. The dose-additive method can be used to reliably evaluate the absorbed doses of cumin and white pepper. The 3rd polynomial function can be used to fit the data. Long-term decay of the radiation-induced radical has a marked influence on dose assessment and leads to an underestimation of the dose.     

Solid-phase microextraction coupled with high performance liquid chromatography: a complementary technique to solid-phase microextraction-gas chromatography for the analysis of pesticide residues in strawberries

Solid-phase microextraction coupled with high performance liquid chromatography has been studied for the analysis of methiocarb, napropamide, fenoxycarb and bupirimate in strawberries. The strawberries were blended and centrifuged. Then, an aliquot of the resulting extracting solution was subjected to solidphase microextraction (SPME) on a 60 μm polydimethylsiloxane /divinylbenzen e (PDMS/DVB) fibre for 45 min at room temperature. The extracted pesticides on the SPME fibre were desorbed into SPME/ high performance liquid chromatography (HPLC) interface for HPLC analysis with diode-array detection (DAD). The method is organic solvent-free for the whole extraction process and is simple and easy to manipulate. The detection limits were shown to be at low μg kg^-1 level and the linear response covered the range from 0.05 to 2 mg kg^-1 of pesticides in strawberries with a regression coefficient larger than 0.99. A good repeatability with RSDs between 2.92 and 9.25% was obtained, depending on compounds.     

Utilization of text mining as a big data analysis tool for food science and nutrition

Big data analysis has found applications in many industries due to its ability to turn huge amounts of data into insights for informed business and operational decisions. Advanced data mining techniques have been applied in many sectors of supply chains in the food industry. However, the previous work has mainly focused on the analysis of instrument‐generated data such as those from hyperspectral imaging, spectroscopy, and biometric receptors. The importance of digital text data in the food and nutrition has only recently gained attention due to advancements in big data analytics. The purpose of this review is to provide an overview of the data sources, computational methods, and applications of text data in the food industry. Text mining techniques such as word‐level analysis (e.g., frequency analysis), word association analysis (e.g., network analysis), and advanced techniques (e.g., text classification, text clustering, topic modeling, information retrieval, and sentiment analysis) will be discussed. Applications of text data analysis will be illustrated with respect to food safety and food fraud surveillance, dietary pattern characterization, consumer‐opinion mining, new‐product development, food knowledge discovery, food supply‐chain management, and online food services. The goal is to provide insights for intelligent decision‐making to improve food production, food safety, and human nutrition.     

Scanning the future--ultrasonography as a reproductive management tool for dairy cattle

Application of transrectal real-time ultrasonography as a research tool to study bovine reproduction represents a technological breakthrough that has revolutionized our understanding of reproductive biology in cattle. The widespread adoption and use of ultrasonography for routine reproductive examinations of dairy cattle by bovine practitioners is the next contribution this technology will make to the dairy industry. Assessment of pregnancy status and fetal viability early postbreeding to identify cows that fail to conceive improves reproductive efficiency by decreasing the interval between artificial insemination services and increasing artificial insemination service rate. Early identification of cows carrying twin fetuses will allow for implementation of differential management strategies to abrogate negative effects of twinning during the periparturient period once such strategies have been developed. Ovarian and uterine pathologies not accurately detected via rectal palpation can easily be visualized by ultrasound, and appropriate therapies can be implemented. Determination of fetal sex in utero is useful when coupled with a management decision that justifies the expense of fetal sexing. Development of integrated reproductive management systems that combine ultrasound with new and existing reproductive technologies will further enhance the practical applications of ultrasonography. Development of Extension education programs to train bovine practitioners to use ultrasound for routine reproductive examinations is a critical step toward rapid implementation of this technology into the dairy industry.