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Background Cold plasma (CP) is an emerging technology, which has attracted the attention of scientists globally. It was originally developed for ameliorating the printing and adhesion properties of polymers plus a variety of usage domains in electronics. In the last decade, its applications were extended into the food industry as a powerful tool for non-thermal processing, with diverse forms for utilization. Scope and approach This review presents an overview of recent studies on the application of cold plasma in the food industry. Specific areas discussed include microbial decontamination of food products, packaging material processing, functionality modification of food materials and dissipation of agrochemical residues. The application of CP has also been expanded into areas, such as hydrogenation of edible oils, mitigation of food allergy, inactivation of anti-nutritional factors, tailoring of seed germination performance and effluent management. In addition, the paper provides a summary of plasma chemistry and sources, factors influencing plasma efficiency and strategies for augmentation. Furthermore, key areas for future research are highlighted and salient drawbacks are discussed. Key findings and conclusions The recent studies conducted on the interaction of reactive species with food contact surfaces establish plasma processing as an eco-friendly technique with minimal changes to food products, making it a befitting alternative to traditional techniques. Active researches focused on up-scaling for commercial applications are urgently required. [ABSTRACT FROM AUTHOR]

Background Advanced food processing technologies such as microwave heating have experienced increased popularity, as alternatives to conventional processing methods for diverse applications in the food industry. A new dimension, is the concept of microwave-assisted food processing techniques, which utilize the advantages of microwave energy to overcome the shortcomings of conventional and some emerging food processing methods. Scope and approach This paper reviews some microwave-assisted (MA) food processing technologies, such as MA-ultrasonication, MA-ohmic heating, MA-electron irradiation, MA-freezing, MA-osmotic dehydration, MA-infrared heating, and microwave-vacuum processing (MA-VC). In particular, their effects in terms of enhancing product quality and process efficiency, including principles and mechanisms are discussed. Promising food applications includes drying, extraction, baking, roasting, pasteurization/sterilization, tempering. Future strategies to further widen their applications are highlighted and salient drawbacks are also taken into consideration. Key findings and conclusions In general, the resultant benefits of microwave assistance to conventional or emerging food processing technologies include high thermal efficiency, shorter processing time, reduced operational cost and improved product quality. It is hoped that this paper will increase positive ratings for microwave assisted food processing technologies and promote their adoption by the food industry. However, it is important that appropriate simulation models for process optimization be developed alongside. [ABSTRACT FROM AUTHOR]

Background Food quality and safety is of great concern to governments, the food industry, as well as consumers. Thus, research has been conducted to develop advanced detection techniques instead of traditional methods to provide rapid, non-destructive food quality and safety evaluation and analysis for the industry. Scope and approach As an emerging technology, Raman imaging has been successfully studied in food safety assessment and control. This review provides a comprehensive overview on the applications of Raman imaging in the area of food quality evaluation, assessment of adulterants and contaminants, and detection of pesticides. Other relevant techniques are also reported due to their close relationship with food safety control. Conclusions and key findings With these applications, it is evident that Raman imaging has given promising results and thus could be a powerful technique for food quality surveillance as well as for reducing the occurrence of food safety issues. [ABSTRACT FROM AUTHOR]

Background Most contamination in agricultural and food products (AFP) is caused by undesirable microorganisms and how to detect microbial contaminants in a rapid and reliable way has always been a topic of great interest for researchers. By integrating traditional spectroscopy and digital imaging function into one system, hyperspectral imaging simultaneously providing spectral and spatial information is proposed and could be used as a smart and promising technology for microbial evaluation in AFP. Scope and approach In this review, we summarized the recent progresses and applications of hyperspectral imaging in replacing conventional time-consuming, tedious, labor-intensive and destructive techniques by providing a rapid, real-time, non-destructive and efficient alternative for detecting various microbial contaminants in raw and processed AFP. The great potential and importance of hyperspectral imaging is emphasized and approved with its satisfactory performance in microbial evaluation of various AFP. Key findings and conclusions Although hyperspectral imaging shows some obvious advantages, it still faces challenges in terms of accurate reference value measurement, fast data mining and advanced system development. With the further research and development of optics, it would be expected that efficient multispectral imaging systems would likely be developed and applied for online microbial evaluation in agricultural and food industry. [ABSTRACT FROM AUTHOR]

Abstract: In recent years, hyperspectral imaging has gained a wide recognition as a non-destructive and fast quality and safety analysis and assessment method for a wide range of food products. As the second part of this review, applications in quality and safety determination for food products are presented to illustrate the capability of this technique in the food industry for classification and grading, defect and disease detection, distribution visualization of chemical attributes, and evaluations of overall quality of meat, fish, fruits, vegetables, and other food products. The state of the art of hyperspectral imaging for each of the categories was summarized in the aspects of the investigated quality and safety attributes, the used systems (wavelength range, acquisition mode), the data analysis methods (feature extraction, multivariate calibration, variables selection), and the performance (correlation, error, visualization). With its success in different applications of food quality and safety analysis and assessment, it is evident that hyperspectral imaging can automate a variety of routine inspection tasks. Industrial relevance: It is anticipated that real-time food monitoring systems with this technique can be expected to meet the requirements of the modern industrial control and sorting systems in the near future. [Copyright &y& Elsevier]

Lactic acid bacteria, which are preserved commercially in a frozen or freeze-dried state, play a crucial role in the food industry due to their preservative and health effects. Hence, maintaining highly viable cells in frozen products by reducing the damage caused by freezing is quite important. Power ultrasound has been considered recently as a novel technique for improving the freezing and crystallization processes. In this article, the effects of power ultrasound on the freezing process and the viability of Lactobacillus plantarum subsp. plantarum after freezing were assessed. Freezing was performed in an ultrasonic bath system (25kHz) equipped with a refrigerated circulator. The bacteria were grown in de Man–Rogosa–Sharpe (MRS) broth and transferred into 1.2ml tubing vials. The freezing medium was MRS broth with or without dimethyl sulfoxide (DMSO). Our results indicated that the non-irradiated sample exhibited a high degree of supercooling. Ultrasound irradiation (0.25Wcm−2) for 3s at different supercooled temperatures (−2, −4, −6, −8, −10 and −12°C) caused nucleation to occur close to the irradiation temperature. Lower nucleation temperatures resulted in a shorter phase change stage and reduced the cell viability. A quicker phase change is known to diminish the size of the ice crystals and cause the formation of intracellular crystals, which adversely affect the viability of frozen suspended cells. Ultrasound-assisted irradiation at higher temperatures (−2 and −4°C), on the other hand, increased the viability of the cells significantly. Ultrasound irradiation during the phase change stage of the freezing process (4min) led to a further increase in the viability of the cells while reducing the freezing time. The higher mass transfer rate of water molecules achieved by ultrasound irradiation might have caused the improved viability and faster freezing process observed for the irradiated samples. Our results revealed that ultrasound irradiation during the nucleation stage or phase change step of the freezing process holds promise as a tool to ensure the higher viability of frozen suspended cells. Industrial relevance: Our results revealed that ultrasound irradiation during the nucleation stage or phase change step of the freezing process holds promise as a tool to ensure the higher viability of frozen suspended cells for the industry. [ABSTRACT FROM AUTHOR]

Abstract: This study was carried out for rapid and non-invasive measurement of color distribution in salmon fillet using hyperspectral imaging in long-wave near infrared spectral range (LW-NIR). Successive projections algorithm (SPA) was used to select effective wavelengths. Instead of selecting different sets of effective wavelengths for each color component respectively, instrumental effective wavelengths (IEWs) were identified for the prediction of all three color components, leading to reducing the number of band-pass filters for designing the multispectral imaging system. Meanwhile, predictive effective wavelengths (PEW) were further chosen from IEW to optimize calibration models. The final prediction models were considered as the multiple linear regression (MLR) models with PEW, which resulted in correlation coefficients (r C ) of 0.876, 0.744, and 0.803 for L*, a*, and b*, respectively. Finally, the visualization of color distribution in salmon fillets was achieved. The results demonstrated that LW-NIR hyperspectral imaging is a potential technique to quantitatively measure color distribution of salmon fillet in a rapid and non-invasive way. Industrial relevance: This study was conducted to evaluate the feasibility of a hyperspectral imaging system in the LW-NIR spectral region (964 to 1631 nm) for rapid measurement of color in intact salmon fillets. On the basis of the results and accompanying illustrations presented in this work, the study demonstrated the ability of the method based on LW-NIR hyperspectral imaging to measure color distribution of salmon fillets. This method was a rapid, contact-free, and consistent evaluation, and can be used as a reliable and rapid alternative to traditional colorimeter for measuring color of salmon fillet for the food industry. [Copyright &y& Elsevier]

Process analysis is an important step for online food quality control during food processing. Among the emerging non-destructive examination techniques that offer rapid detection, terahertz spectroscopy has attracted attention in analysing food processes based on various quality parameters. Moreover, calibration and chemometric methods are frequently used for spectral data analysis. The system normally consists of processing equipment and terahertz time-domain spectral imaging (THz-TDS), which often exhibits high prediction accuracy combined with appropriate chemometrics methods. Therefore, terahertz spectroscopy has been considered highly suitable for on-site and in-situ process analysis to enhance manufacturing and thus improve product quality. In this review, applications of THz-TDS in food processes of dehydration, storage, freezing, and fermentation, as well as other areas, are introduced and discussed. Among these, terahertz technology has attracted intensive research for process analysis related to moisture changes, such as dehydration and storage under natural drying conditions. Emerging techniques of THz-TDS with other processing techniques, such as hot air drying (HAD) and microwave vacuum dehydration (MVD), are frequently investigated. Applications in other areas, including analysing fermentation, freezing, and hygroscopic processes, were also reported. For freezing analysis, it is mainly used to analyze (i) the effect of repeated freezing and thawing on meat and (ii) the growth rate of ice crystals. In analysing fermentation processing, although most of the research has confirmed the feasibility of THz-TDS, further investigation regarding the accuracy is still awaited. The combination of THz-TDS with calibration and chemometrics has been widely employed in analysing the non-linear changes of quality attributes during food processing with the emergence of numerous related research in recent years. It is highly suitable for analysing moisture content and other polar substances such as hydrogen sulfide and ammonia. Despite such high performance, drawbacks of high cost, interference from high moisture content, and high disturbance of other constituents such as protein are still significant obstacles to the universalization of THz-TDS. • Recent novel research on THz-TDS in food processing analysis was reviewed. • THz-TDS shows the potential for online monitoring of fermentation processes. • Chemometrics and algorithms significantly improve the accuracy of THz-TDS. • Drawbacks and future perspectives of THz-TDS were proposed and discussed. [ABSTRACT FROM AUTHOR]

Computer vision has emerged as a useful alternative to manual expert grading of meat in recent years. Manual grading by experts has a number of essential flaws that can be effectively mitigated with computer vision technology. Computer vision technology is a simple and affordable alternative that, while requiring some expertise, is not excessively technologically demanding. Computer vision technology has shown key attributes of flexibility and ease of compatibility allowing a wide range of meat quality assessment challenges to be successfully tackled. The simplest approaches involving visible light imaging and explicit statistical modelling have proven adequate on the vast majority of occasions. On the other hand, for difficult tasks, more expensive non-visible wavelength imaging and implicit statistical modelling are required. In addition, fully automatic image segmentation still remains a difficult problem in many instances, although image processing is becoming more powerful particularly as computationally demanding texture characterisation algorithms become more viable as computation speeds increase. Finally training and testing a computer vision system will require considerable groundwork as a substantial amount of image and independent meat quality data will be required for good model calibration and validation. [Copyright &y& Elsevier]

Abstract: A new structural method was developed to characterise texture of colour meat images. Structural primitives or region-primitives were constructed using a region-growing method with a global and automatically calculated threshold. A total of eight textural features under the consideration of size, orientation, and contrast, which are the primary factors of human perception of texture pattern, were obtained from the region-primitives. An experiment was set up to classify the texture pattern of a set of 60 cooked meat colour images consisting of 20 beef images, 20 lamb images, and 20 pork images using texture features obtained from the proposed region-primitive method and run-length matrix method, respectively. The proposed region-primitive method (error rate: 18.3%) was found to perform better than the run-length matrix method (error rate: 35.0%). Results also indicated that the texture features obtained by the proposed method carried adequate texture information for classification and that the proposed region-primitive method could be potentially used for the characterisation of irregular textural pattern in cooked meat images, which was inapproachable by conventional structural texture analysis techniques. [Copyright &y& Elsevier]

This paper reviews the techniques available for image feature extraction and their applications in the food industry up to now according to the four major kinds of image features, i.e., colour, size, shape, and texture. Results from previous studies have shown that each kind of image features contained important information required for food quality evaluation and inspection. Furthermore, the proper combination of different kinds of image features can normally increase the accuracy of the evaluation results; sometimes such a combination might even reveal some quality attributes that cannot be identified by using only a single kind of image features. Further to this, the feature extraction techniques were compared with each other, and their advantages, disadvantages, and feasibilities in different applications were also discussed. [Copyright &y& Elsevier]

Abstract: Rice is an important staple food, and often used in ready meals, which should be cooled rapidly after cooking. In the current research, cooked rice was cooled by vacuum cooling, air blast cooling, cold room cooling and plate cooling. It was found that vacuum cooling could chill the cooked rice with much shorter time but with higher weight loss than the other cooling methods. Vacuum cooling of the rice under different conditions could lead to changes of the cooling time and weight loss. If lower final pressure was used in the cooling process or less weight of cooked rice was vacuum cooled, shorter vacuum cooling time and lower weight loss could be obtained. If the rice was cooked for longer boiling time or was vacuum cooled with excess water, the cooled rice could have higher moisture content, but the cooling time would be prolonged significantly. Spraying water during vacuum cooling did not significantly prolong the cooling time, but increased the moisture content of cooled rice. On the other hand, longer boiling time, cooling with excess water and spraying water could reduce hardness of the cooled rice significantly. Only spraying of water could cause significant reduction in the adhesiveness of the rice. [Copyright &y& Elsevier]

Abstract: The principle of vacuum cooling is based on rapid evaporation of part of the moisture of the product under vacuum. Vacuum cooling can be used to shorten processing time, extend product shelf life, and improve product quality and safety. Traditionally, vacuum cooling is used in the agricultural industry to pre-cool leafy vegetables and mushroom in order to rapidly remove field heats. Recently, vacuum cooling has been applied to cool viscous food products and bakery products in the food industry, and tuna in the fish industry. Food safety concern has driven cooked meat manufacturers to explore new method to reduce cooling time, which has consequently led to a comprehensive research study of vacuum cooling of large cooked meat joints in the past few years including mathematical modelling of the vacuum cooling process using finite element method and computational fluid dynamics (CFD), especially thorough research work has been carried out by the Food Refrigeration and Computerised Food Technology (FRCFT) Research Group in National University of Ireland. Currently, research studies on vacuum cooling of ready meal components have also been conducted in FRCFT Research Group. This paper first discusses the principles and equipment of vacuum cooling and critically analyses the advantages and disadvantages of this technique. Much effort is then spent on reviewing the development of this technology for the agri-food industry, in particularly, the latest research results from the FRCFT Research Group, which have carried out extensive research work since 1997 funded by the Non-Commissioned Food Research Programme and the Food Institutional Research Measures administered by the Irish Government Department of Agriculture and Food. Future prospects of research and development of vacuum cooling technology is finally addressed. [Copyright &y& Elsevier]

Computational fluid dynamics (CFD) is a powerful numerical tool that is becoming widely used to simulate many processes in the food industry. Recent progression in computing efficacy coupled with reduced costs of CFD software packages has advanced CFD as a viable technique to provide effective and efficient design solutions. This paper discusses the fundamentals involved in developing a CFD solution. It also provides a state-of-the-art review on various CFD applications in the food industry such as ventilation, drying, sterilisation, refrigeration, cold display and storage, and mixing and elucidates the physical models most commonly used in these applications. The challenges faced by modellers using CFD in the food industry are also discussed. [Copyright &y& Elsevier]

Abstract: Texture is an important image feature and has been applied greatly in the food industry for quality evaluation and inspection. Recent applications of texture-analysis techniques in the food industry were reviewed in the current paper. There are four different types of texture, i.e. statistical texture, structural texture, model-based texture, and transform-based texture. Statistical texture can be obtained using statistical approachs from the higher-order of pixel grey values of images while structural texture is acquired through some structural primitives constructed from grey values of pixels. Transform-based texture can be obtained by using statistical measurements from the images transformed with certain methods. Model-based texture can be attained by calculating coefficients from a model based on the relationship of the grey values between a pixel and its neighboring pixels. Among them, statistical texture is the most widely used one in the food industry for its high accuracy and less computation time. Transform-based texture and model-based texture are also used, although not as popular as statistical texture. However, structural texture is rarely used in the food industry. Due to the limited understanding of image texture up to now, it is difficult to identify which kind of method is the best for certain application. Therefore, it is expected that by employing different methods together, final results can be improved. [Copyright &y& Elsevier]

With increased expectations for food products of high quality and safety standards, the need for accurate, fast and objective quality determination of these characteristics in food products continues to grow. Computer vision provides one alternative for an automated, non-destructive and cost-effective technique to accomplish these requirements. This inspection approach based on image analysis and processing has found a variety of different applications in the food industry. Considerable research has highlighted its potential for the inspection and grading of fruits and vegetables. Computer vision has been successfully adopted for the quality analysis of meat and fish, pizza, cheese, and bread. Likewise grain quality and characteristics have been examined by this technique. This paper presents the significant elements of a computer vision system and emphasises the important aspects of the image processing technique coupled with a review of the most recent developments throughout the food industry. [Copyright &y& Elsevier]

Numerical modelling technology offers an efficient and powerful tool for simulating the heating/cooling processes in the food industry. The use of numerical methods such as finite difference, finite element and finite volume analysis to describe the heating/cooling processes in the food industry has produced a large number of models. However, the accuracy of numerical models can further be improved by more information about the surface heat and mass transfer coefficients, food properties, volume change during processes and sensitivity analysis for justifying the acceptability of assumptions in modelling. More research should also be stressed on incorporation of numerical heat and mass transfer models with other models for directly evaluating the safety and quality of a food product during heating/cooling processes. It is expected that more research will be carried out on the heat and mass transfer through porous foods, microwave heating and turbulence flow in heating/cooling processes. [Copyright &y& Elsevier]

Computational fluid dynamics (cfd) is a simulation tool, which uses powerful computer and applied mathematics to model fluid flow situations for the prediction of heat, mass and momentum transfer and optimal design in industrial processes. It is only in recent years that cfd has been applied in the food processing industry. This paper reviews the application of cfd in food processing industries including drying, sterilisation, refrigeration and mixing. The advantages of using cfd are discussed and the future of cfd applications is also outlined. [Copyright &y& Elsevier]

The performance of slow air, air blast and water immersion cooling methods in the cooked meat industry was evaluated by a validated finite element model. The cooked meat joints in commercial and controlled geometries were cooled by these three traditional cooling methods under different operating conditions. Simulations showed that it is difficult for traditional cooling methods to cool the large commercial cooked meat joints because the poor thermal conductivity of meat controls the cooling rate. It takes about 8.5, 6.5 and 3.5 h for air blast cooling with an air velocity of 3 m/s and an air temperature of 0°C to reduce the cooked meat joints in a typical ellipsoid shape with the weights of 8, 5 and 2 kg from the core temperature of 74–10°C, respectively. For water immersion cooling with water velocity of 0.15 m/s and water temperature of 0°C, the cooling times can be reduced to 7, 5 and 2.8 h, respectively. A rapid cooling can be achieved by controlling the shortest dimension. For cooling a cooked meat joint with the weight more than 5 kg by air blast cooling to meet the cooling requirements specified in cook-chill guidelines, the infinite slab shape with the shortest dimension of 5 cm and an infinite cylinder with the diameter of 10 cm was chosen. For water immersion cooling, the shortest dimension of the brick-shaped meat joints could be increased to near 10 cm. [Copyright &y& Elsevier]

The three-dimensional transient heat transfer of roasted meat during air blast cooling process was modelled by the finite element method for evaluating the cooling performance. Moisture loss rate was considered in the model to account for the weight loss during air blast cooling. The model includes the variations in physical properties of the roasted meat and in operating conditions during the air blast cooling process. A user-friendly computer program developed in visual C++ by the authors was used to solve the model. The model was validated by comparing the numerical solutions with the experimental results. The comparison showed that the maximum deviation between the predicted and experimental core temperatures was within 2.4°C. The deviation between the predicted and experimental total weight loss was 2.5%. The model and software can also be used to analyse other thermal processing procedures of foods with some modifications. [Copyright &y& Elsevier]

A computer vision system was used to evaluate the melting property of cheese. The method is suitable for both cheddar and mozzarella cheese. The effect of cooking time (0–20 min) and temperature (70–200°C) on the melting degree and melting rate of cheddar and mozzarella cheese was investigated and the melting property of both cheeses were compared. Both cheddar and mozzarella cheese melted rapidly at the initial stage of cooking and melting slowed down in about 3–4 min. Maximum melting degree and melting rate occurred at about 130–160°C. Extended cooking and cooking at high temperature may cause reduced melting. Cheddar cheese melted more rapidly and considerably than mozzarella cheese at all cooking temperatures. [Copyright &y& Elsevier]

Freezing and refrigeration play an essential role in the quality preservation of perishable food products, however, the undesired ice or frost accretion on freezing facility surfaces results in high-energy consumption with adverse economical and environmental effects. Recently, biomimetic surfaces with superwettability have been proven to delay icing and frosting on cold substrates or to de-ice and de-frost easily, with the potential of supplementing or even replacing conventional de-icing or defrosting technologies. Applying this technology to the freezing and cold chain of food can significantly reduce energy consumption and enhance the freezing efficiency for the food industry. In this review, the anti-icing mechanism of biomimetic surfaces with superwettability including water repellency, icing or frosting retarding and ultralow ice adhesion strength are presented. Recent research efforts made to improve mechanical stability, practicality and the safety of superhydrophobic surfaces (SHSS), as well as slippery liquid-infused porous surface (SLIPS), are discussed. The potential applications of bionic surfaces for food refrigeration industry are also highlighted, including the development of energy-saving heat exchanger and applications in frozen food production and preservation. SHSS show the capability to retard freezing and SLIPS possess excellent de-icing performance for ultralow ice adhesion. Since the bare nano-coating is easily worn out, the adhesive enhanced superhydrophobic nano-coatings could endow the coating with robust and longlasting anti-icing capacity. The future trends of bionic anti-freezing materials development should mainly focus on non-toxicity, robust mechanical stability, economy and scalability. • We discuss the anti-icing mechanism of biomimetic non-wetting surfaces. • We present advances in developing robust and eco-friendly anti-icing materials. • We propose potential applications of bionic modified surfaces in the food industry. • Future efforts should be devoted to industrialize bionic anti-freezing materials. [ABSTRACT FROM AUTHOR]

Abstract Background Advanced glycation end-products (AGEs) are a sort of complex products formed by the Maillard reaction between the carbonyls of reducing sugars and the free amino groups of amino acids. Some of AGEs ingested through foods accumulate in human body, causing a series of chronic diseases. However, due to the complex and varied structures, there is lack of systematic reviews on dietary AGEs. Scope and approach This paper summarizes the aspects of AGE formation, influencing factors and hazards, as well as their distribution in foods. The detecting methods available for dietary AGEs are also highlighted. Finally, the main challenges and future efforts for studying AGEs in foods and their effects on health are discussed. Key findings and conclusions The study of AGEs has great significance in foods and human health. Although great advances in understanding the effects of AGEs in human body are made, more unequivocal guidance for dietary AGEs to people should be provided in future. Highlights • We describe fundamentals for advanced glycation end-products (AGEs). • We discuss AGEs influencing factors and their distribution in foods. • We explain details of effects of AGEs in human body. • We highlight methods available for measuring and quantifying AGEs in foods. [ABSTRACT FROM AUTHOR]

Background Food safety and quality have gained much attention in recent years and the capability to evaluate food quality and safety in a sensitive, rapid, and reliable manner is of great importance in the food industry. Therefore, surface-enhanced Raman scattering (SERS) with the advantages of excellent sensitivity, high selectivity, non-destructive nature and significant enhancement to identify the target has demonstrated a great potential for quick detection of chemical contaminants, chemical constitutes, and pathogens in food samples. Scope and approach The enhancement of Raman signals for SERS is not only related to the interactions between substrates and samples but also the functionalization of substrates to gain SERS active substrates. In the present review, different types of substrates are briefly discussed, functionalization techniques for SERS active substrates are discussed, and applications of functionalized SERS substrate in food samples are presented. Conclusions and key findings It is evident that functionalization techniques for improving SERS substrates have given encouraging outcomes, which provides possibility for identifying multiple target analytes within a complex matrix, and thus could be used as a powerful analytical tool in real-world applications in food safety analysis as well as for enhancing food quality surveillance. [ABSTRACT FROM AUTHOR]

This study aimed to develop an alternative technique for rapid, accurate and non-invasive determination of gross energy density values of salmon fillets based on hyperspectral imaging (900–1700 nm). Spectral data were extracted from the hyperspectral images with outlier pixels removed. Good performances were achieved with r P of 0.906 and 0.909, and normalized RMSEP of 6.768% and 7.064% for partial least squares regression (PLSR) and epsilon-support vector regression (epsilon-SVR) analysis, respectively. The optimized stepwise-PLS model built with four wavelengths (931, 1001, 1135 and 1168 nm) yielded good results with r P of 0.908 and normalized RMSEP of 6.871%. The distribution maps for visualizing energy density indices in all portions of the salmon fillet were subsequently generated. The overall results confirmed the successful development of a rapid and non-destructive technique using hyperspectral imaging for determining energy value of salmon fillets, and the provision of an alternative method for caloric density measurement for the food industry. [ABSTRACT FROM AUTHOR]

There is a great interest in developing optical techniques that have the capability of predicting quality attributes, safety parameters and authenticity in real-time assessment. Recently, hyperspectral imaging technique has been widely used for rapid and non-destructive inspection of various food products. Although the technique is currently in an early development stage, its potential is promising. Due to the extensive time needed for the processing of the large volumes of data, hyperspectral imaging technique cannot be directly implemented in an online system. However, selecting some feature wavelengths from hyperspectral images can be useful to develop a multispectral imaging system, which can meet the speed requirement of industrial production. Indeed, the success of multispectral imaging heavily depends on the effectiveness of hyperspectral imaging (HSI) for providing the feature wavelengths. If the high dimensionality of hyperspectral data can be reduced properly in order to design/form a low-cost multispectral imaging sensor based on some selected feature wavelengths for certain applications, the technique would certainly be incomparable for process monitoring and real-time inspection. This review first introduces the fundamental steps for selecting feature wavelengths from hyperspectral data and then describes the feature wavelengths derived from hyperspectral imaging applications to make a more effective and efficient multispectral real-time imaging system. It is anticipated that this review can act as a basis for researchers and industry for further development of online multispectral inspection system for quality, safety and authenticity of muscles food. [ABSTRACT FROM AUTHOR]

Even though raw and processed crops are consumed as food worldwide, one-third of these agricultural produces go as waste or by-products. These by-products contain several valuable components, such as pectin, that can be valorized in the food processing industry through waste recycling to improve resource efficiency. However, the conventional methods (e.g., acid extraction of pectin) have limitations, such as low yield, and are energy-intensive and associated with environmental problems. Therefore, the possibility of using emerging processing technologies for pectin extraction has attracted wider attention. This paper aims to describe the status of the valorization of food and agricultural by-products through the application of emerging processing methodologies with specific attention to pectin extraction. In this regard, papers published in this area of research during the past decade were retrieved from scientific databases and their findings were analyzed. Emerging thermal (e.g., microwave and ohmic heating) and non-thermal (e.g., moderate electric field, pulsed electric field, high-pressure processing, and ultrasound), as well as combinations of these technologies (e.g., a combined effect of microwave and ultrasound) are among the innovative approaches that have been used for pectin extraction. These methodologies can result in higher extraction yields and produce pectin with a desirable degree of esterification. However, the industrial application of these technologies can be challenging at this moment due to relatively high capital costs, limited professional expertise, and inadequate data on process upscaling. Therefore, research on up-scaled versions and further training in this area of food processing are recommended. [Display omitted] • Pectin extraction (PE) is a valorization approach for agricultural by-products. • Microwave and ohmic are energy/time-saving emerging processing technology (EPT) for PE. • Pulsed electric field, high-pressure, and ultrasound accelerate PE through non-thermal effects. • Combination of EPT can boost the pectin yield and physicochemical qualities. • Upscaling studies are needed for PE through EPT at industrial scales. [ABSTRACT FROM AUTHOR]

Abstract: Power ultrasound has been proven to be useful in promoting the nucleation of ice and affecting the crystal growth phenomenon during freezing. In the present research, the effect of ultrasound assisted freezing on the ice crystal size distribution of agar gel samples was studied. The samples were frozen in an ethylene glycol–water mixture (−20°C) in an ultrasonic bath system. To evaluate nucleation, ultrasound (25kHz) was applied for 3s at different temperatures during supercooling. Moreover, irradiation was carried out for different durations (90, 180 and 270s), intensities (0.07, 0.25 and 0.42Wcm−2) and duty cycles (30, 50 and 70%) in the phase change period. Results indicated that ultrasound irradiation at different temperatures was able to initiate nucleation in agar gel samples after a short delay. Microstructure evaluation of the samples revealed that the size distribution of ice crystals was affected by ultrasound induced nucleation temperature. Decreasing the nucleation temperature resulted in smaller ice crystals. Irradiation in the phase change stage significantly affected the microstructure as well. Smaller ice crystals were observed in comparison with the non-irradiated sample. However, no regular relationship between the evaluated parameters (intensity, duration and duty cycle) and the crystal sizes was detected. More investigations are needed to study the mechanism of freezing and the rheology of the final product as affected by ultrasound irradiation. Industrial relevance: The results of this study suggested that ultrasound can be used as a potential tool to decrease the size of ice crystals in solid foods for the food industry. [Copyright &y& Elsevier]

Abstract: Garlic powder with high allicin content was prepared using microwave–vacuum and vacuum drying as well as microencapsulation in order to protect alliinase activity throughout the human stomach and improve the ratio of alliin transforming into allicin. The results showed that the optimal microwave–vacuum drying condition was drying for 3min under the microwave output power 376.1W, then 282.1W for 3min, followed by 188.0W for 9min, and finally for 3min under the output power 94.0W. The thiosulfinates retention after drying was 90.2%. Following drying, garlic powder was microencapsulated by modified fluidized bed technique. Scanning electron microscope revealed good integrity and core materials that were embedded in microcapsules. Studies on the release kinetics of microencapsulated garlic granulates in vitro using simulated intestinal fluid indicated that release of garlic powder could be controlled in intestine by passing through human stomach conditions. [Copyright &y& Elsevier]

Abstract: As a consequence of market competition, the production and manufacture of cheese products are at the stage of innovative dynamics. Pasteurized cheese with vegetable ingredients is one of the new products that may be added to sandwiches, salads, sauce, toast and pizza. Since vegetable ingredients can improve the nutritive value and flavour of cheese, it will probably become more and more popular in the future. Such new products require new techniques for monitoring and evaluating their quality in order to satisfy the increased awareness and expectations of consumers. Computer vision methods have been used increasingly in the food industry for inspection and evaluation purposes as they provide a rapid, economical, consistent and objective assessment. The aim of this study was to develop a computer vision method for inspecting two major quality attributes of pasteurized cheese, i.e. the distribution and amount of ingredients. An image pre-processing algorithm was first developed to delete the border area of cheese. Next a three-step method for ingredient extraction was developed, comprising colour quantification, ingredient location, and mask operation. Finally, the distribution and amount of each ingredient was calculated automatically. Two kinds of pasteurized cheese were evaluated using the above method, i.e. (a) cheese with garlic and parsley and (b) cheese with a mixture of vegetables composed mainly of pepper and parsley. It was found that the distribution and amount of ingredients in the first set of samples were determined within an accuracy of over 88%, compared with the results of a sensory method. As for the second set of samples, accuracies of over 81% and over 71% were achieved for measuring the distribution and amount of ingredients, respectively. [Copyright &y& Elsevier]

• Tomato slices were pretreated by plasma functionalized water (PW) before drying. • PW accelerated moisture transfer and shortened drying time. • PW was combined with osmotic dehydration liquid as a hurdle pretreatment technique. • The hurdle technique improved drying and bioactive compound retention. The effects of pretreatments using plasma functionalized water (PW), osmodehydration (OD), and combined plasma functionalized water and osmodehydration (PO) on the drying characteristics, physicochemical and bioactive components of tomato slices during hot air drying at an air temperature of 55 °C and velocity of 1.5 m/s were evaluated. Results revealed that PW pretreatment led to an increase in lycopene compared to fresh samples, and shortened drying time, improved ascorbic acids, TPC, TFC, acidity, rehydration, porosity and hue, but reduced TSS, compared to dried control samples, while OD resulted in lycopene degradation during pretreatment, and prolonged drying time, increased TSS, but lowered acidity, rehydration, porosity and hue, compared to dried control samples. On the other hand, PO was found to overcome the shortcomings of OD with enhancement in the lycopene during pretreatment, and showed accelerated moisture transfer, improved bioactive, acidity, porosity, rehydration, hue and texture, but decreased TSS, when compared to dried control samples. Overall, the results showed the promising potential of PW and PO pretreatments for enhancing drying efficiency and product quality for the food industry. [ABSTRACT FROM AUTHOR]

Abstract: The effects of applying an electric field (EF) treatment with 1kV/cm (50Hz) on brandy stored in 5-L and 2-L oak barrels, respectively, for over 14months to simulate the natural aging process were investigated in this paper, as compared with brandy sample naturally aged in 225-L oak barrels. Results demonstrated that the content of phenol compounds in brandy such as tannins, total phenols as well as volatile phenols were significantly increased after treatment by EF, with tannin concentration of the brandy treated by EF being 54.4% and 43.9% higher than those of the control brandy after 14months of maturation in 5-Land 2-L barrels, respectively. On the other hand, the chromatic aberration of the brandy treated by EF for 14months was 19.2% and 24.9% higher than the control in 5-L and 2-L barrels, respectively. It was also demonstrated that the EF treated samples in 5-L barrels for 7months and in 2-L barrels for 5months exceeded the content of tannins of those naturally aged for 12months in 225-L oak barrels used in the brandy industry. Ten kinds of phenol compounds were identified, which could be divided into three categories based on clustering analysis, and the kinetic model of oak phenol compounds extracted by brandy demonstrated that EF treatment played a positive role in accelerating the extraction of phenol compounds and its effect was more significant than the size of barrel. The current study demonstrated that application of EF treatment directly on oak barrel is a promising and feasible technology to speed up brandy maturation. Industrial relevance: The current study demonstrated that application of electric field treatment directly on oak barrels is a promising and feasible technology to speed up brandy maturation for the industry. [Copyright &y& Elsevier]

Abstract: Recently, computational fluid dynamics (CFD) has been frequently applied in many fields relating to fluid flow, and it has been shown that CFD is useful in these fields. The cooling rate and quality of foodstuffs in a cold store are highly dependent on the temperature field which is closely related to flow field. However, the flow field designed by using traditional methods, using a lot of time and cost without reliable and repeatable results, is not good enough. In this paper, a two-dimensional mathematical model for the inside a minitype constructional cold store [4.5m (l)×3.3m (w)×2.5m (h)] was proposed and a related computer program with SIMPLE algorithm and crisscross girding technique were developed. The simulation results reflected the characteristics of airflow and temperature distribution. After that, several design parameters (corner baffle, the stack mode of foodstuffs, etc.) which would affect the flow field in the cold store were analyzed. The results of calculation indicated that all these design parameters especially the stack mode of foodstuffs influenced the flow and temperature fields inside the cold store greatly. It was demonstrated that CFD was a powerful tool for designing and optimizing the flow field in cold store. [Copyright &y& Elsevier]