Refractance Window Drying of Apple Slices: Mass Transfer Phenomena and Quality Parameters Abstract The present study investigates the effect of Refractance Window (RW) drying at different temperatures (60 °C, 70 °C, 80 °C, and 90 °C) on drying characteristics and quality of apple slices and its comparison with hot air (HA) drying. Results showed that RW drying requires a shorter time (~ 25–37.5%) as compared to HA drying under similar conditions of drying. Also, RW drying at 90 °C resulted in higher retention of ascorbic acid (96%), without any significant change in color (ΔE = 5.5), compared to freeze drying. The microstructure analysis showed porous structure in RW-dried slices as compared to HA-dried ones. The influence of drying conditions on moisture diffusion was estimated using Fick’s, anomalous diffusion, and Dincer and Dost models. The values of moisture diffusivity (from 2.75 × 10−9 to 1.14 × 10−8 m2 s−1) obtained with the Dincer and Dost model were higher for RW as compared to HA and also were higher with respect to other models employed. Anomalous diffusion and Dincer and Dost models showed excellent agreement (R2 > 0.989) between experimental and predicted moisture ratios. This study showed that RW drying could effectively be used to dry thin layers of heat-sensitive fruits such as apple in a shorter time with better product quality as compared to HA drying.

Application of Fuzzy Logic in Sensory Evaluation of Food Products: a Comprehensive Study Abstract Sensory evaluation plays a vital role in the assessment of acceptance of novel food products and preferences for different cuisines. This process provides significant and valuable information to the food-processing industries and food scientists regarding the sensory quality of food products. Traditional techniques generally employed for the sensory evaluation assess only in a qualitative sense and cannot perform a precise quantitative assessment. However, recently, novel techniques such as fuzzy set theory have been effectively used in assessing the sensory characteristics of various traditional as well as novel food products developed through fortification and modified processing techniques. The aim of the fuzzy set theory is to treat ambiguous phenomena mathematically and express the degree of incomprehensibility in human thinking along with connecting it to a real number. Furthermore, fuzzy logic mimics human behavior for reasoning and decision-making. In fuzzy modeling, linguistic entities such as “not satisfactory, fair, medium, good and excellent” are employed for describing the sensory attributes of food products (including color, aroma, taste, texture, and mouthfeel) obtained through subjective evaluation, which are combined with the accurate and precise data attained through objective evaluation to draw conclusions regarding acceptance, rejection, and ranking, along with strong and weak characteristics of the food under study. This analysis also assists in finding the preference of quality attributes and sets criteria for acceptance or rejection of the newly developed foods. This review provides an overview of the application of fuzzy concepts to the sensory evaluation of traditional and novel food products (often enriched with nutraceuticals) in the food industry, along with the corresponding advantages.

Biocontrol of Gray Mold of Cherry Tomatoes with the Volatile Organic Monomer from Hanseniaspora uvarum , Trans -Cinnamaldehyde Abstract Botrytis cinerea is one of the most destructive pathogens of cherry tomatoes during preharvest and postharvest phase. Our previous study demonstrated that volatile organic compounds (VOCs) produced by Hanseniaspora uvarum could markedly suppress the mycelium growth and conidia germination of B. cinerea. However, the main inhibitory VOCs of H. uvarum are not fully clear. In this study, a total of 21 volatile organic monomers (VOMs) of H. uvarum were tested for their antifungal activity against B. cinerea in vitro. It was found that trans-cinnamaldehyde, 2-nonanone, ethyl caprylate, benzyl alcohol, hexanoic acid, hexyl alcohol, isobutyl acetate, ethyl propionate, isoamyl acetate, ethyl 2-methylbutyrate, phenethyl alcohol, ethyl acetate, 4-ethylphenol, 3-phenyl-1-propanol, ethyl cinnamate, 3-methyl-1-butanol, and ethyl 3-hydroxybhexanoate could significantly inhibit mycelium growth within 3 days at higher concentrations, whereas ethyl 3-hydroxybutyrate, ethyl caprate, decanoic acid, and lauric acid exhibited a lower inhibition. Furthermore, the five VOMs, including trans-cinnamaldehyde, 2-nonanone, ethyl caprylate, benzyl alcohol, and hexanoic acid, also had the efficiency on inhibiting conidia germination. In particular, trans-cinnamaldehyde was the best inhibitor of mycelium growth and conidia germination. Hence, trans-cinnamaldehyde was also tested in vivo as postharvest biofumigants. In vivo assay showed that trans-cinnamaldehyde could significantly reduce B. cinerea infection of cherry tomatoes and maintain fruit hardness, color, total soluable solids, and titratable acidity under conditions of artificial and natural infection. Collectively, these results indicated that trans-cinnamaldehyde, the main inhibitory VOMs of H. uvarum, has the potential for effectively controlling postharvest gray mold of cherry tomatoes and maintaining fruit quality in commercial application.

Influences of Blanching and Freezing Pretreatments on Moisture Diffusivity and Quality Attributes of Pumpkin Slices During Convective Air-Drying Abstract In this study, the relationship between moisture diffusivity in convective air-drying and cellular structure through blanching and freezing pretreatment and quality attributes of dried pumpkin slices were evaluated to obtain necessary information for designing appropriate drying and pretreatment conditions. The results suggest that the loosely bound structure of cell walls due to blanching and pores in the tissue formed by ice crystals during freezing increased moisture diffusivity. In addition, the functional and structural damage of cell membranes by the pretreatments, shown by the electrical impedance analysis, is likely involved in moisture diffusivity during drying. In particular, the sample pretreated by both blanching and freezing showed significantly higher values of moisture diffusivity compared to other samples. With regards to quality attributes, a decrease in color lightness due to starch gelatinization during blanching dramatically affected the color characteristics of the dried product. Starch gelatinization due to blanching and the formation of pores during freezing significantly influenced the structure of the samples after drying, which affected the rehydration rates and mechanical properties.

Effect of Combined Ultrasonication and Modified Atmosphere Packaging on Storage Quality of Pakchoi ( Brassica chinensis L.) Abstract Feasible use of ultrasonic treatment (UT) in combination with modified atmosphere packaging (MAP) to preserve pakchoi was evaluated. Pakchoi was treated with ultrasound (30 kHz) for different periods of time (5 min, 10 min, and 15 min) prior to MAP (with 5% O2 + 10% CO2 + 85% N2); the treated vegetables were then stored at 4 °C for 30 days. UT in combination with MAP could retard an increase in the total number of colonies in pakchoi during the storage. UT-10 min decreased the initial total number of colonies in pakchoi from 7.11 to 6.01 log CFU/g and effectively slowed down the increase in mass loss, yellowing, cell membrane permeability, and malondialdehyde content of the stored vegetable; such a treatment also slowed down the decrease in total soluble solids and losses of ascorbic acid and chlorophylls. The synergistic effect of UT and MAP results in effective reduction of peroxidase and polyphenol oxidase activities. In conclusion, UT-10 min + MAP was the best method to preserve pakchoi for 30 days.

Biochemical and Techno-Functional Properties of Protein- and Fibre-Rich Hybrid Ingredients Produced by Dry Fractionation from Rice Bran Abstract Rice bran is an underutilized side-stream from white rice production, rich in protein and dietary fibre. The aim of the work was to study dry fractionation as a novel approach to enrich protein from non-heated, supercritical carbon dioxide–extracted milled rice bran. One-step air classification allowed protein enrichment from an original 18.5% up to 25.7% in the fine fraction. Alternatively, air classification of the non-milled raw material resulted in a fine fraction (19.7% protein) that was according to microscopy analysis free of pericarp structures, and a coarse fraction containing protein-rich aleurone and germ particles and pericarp structures. Further milling and air classification of the coarse fraction resulted in higher protein enrichment (to 27.4%). All the fine fractions produced by dry fractionation were also enriched in soluble dietary fibre whereas starch content was decreased. Additionally, the fine fractions showed improved protein solubility and colloidal stability and, thus, elevated applicability in food products as compared to the non-fractionated raw material.

Encapsulation of Bioactive Ingredients by Extrusion with Vibrating Technology: Advantages and Challenges Abstract Bioactive ingredients are present in functional foods and provide benefits to consumer health. However, for these compounds to be effective in the human organism, their bioactive features must be preserved during food processing and uptake by the organism. An effective technology to maintain bioactivity is encapsulation, which uses a coating material to protect bioactive ingredients. Not all encapsulation techniques are suitable for the effective protection of bioactive ingredients due to stages in the technique that might damage the bioactivity of the encapsulated ingredient. However, extrusion with vibrating technology has proven to be a technique with simple stages, thus enabling the formation of resistant microcapsules and maintaining the bioactivity of the encapsulated material. The aim of this revision is to show the state of the art on protection of bioactive ingredients using the encapsulation process by extrusion with vibrating technology. Therefore, the characteristics of vibrating technology in encapsulation by extrusion shall be addressed as well as the wall materials used, highlighting the features of the microcapsules obtained. For that, recent studies that have used the method in question specifically to protect bioactive ingredients will be discussed. Vibrating technology associated with extrusion, combined with a previous determination of parameters of suitable equipment and wall materials, allows for obtaining homogenous-sized and shaped microcapsules which provide effective protection to the bioactive compound.

Characterization of Quinoa Defatted by Supercritical Carbon Dioxide. Starch Enzymatic Susceptibility and Structural, Pasting and Thermal Properties Abstract Quinoa has recently been considered as an alternative oilseed crop due to the quality and quantity of its lipid fraction. Supercritical fluid extraction (SFE) was used as a green process to extract quinoa oil without solvent residues. Defatted quinoa flour is a potentially valuable raw material whose performance as food ingredient needs to be established. Structural, physicochemical, pasting, and thermal properties of quinoa (cv. Titicaca) defatted by supercritical CO2 extraction (DQ-SCCO2) were characterized. In vitro starch enzymatic susceptibility was also evaluated. Full fatted quinoa (NDQ) and quinoa defatted by hexane extraction (DQ-HX) were also evaluated in parallel. DQ-SCCO2 showed a disrupted and microporous structure due to the pressurization/depressurization of CO2 in SFE. However, its viscometric profile was very similar to that of NDQ, while that of DQ-HX was significantly lower. This denotes a physical/thermal modification of the flour as a result of the higher temperature applied during hexane extraction, 68 °C, versus 40 °C in SFE. Defatted samples showed lower pasting temperatures (4–5 °C) and higher amylopectin retrogradation extent than NDQ. Quinoa showed a very high enzymatic susceptibility regardless its lipid content; 90% of the starch was hydrolyzed by digestive enzymes in 20 min in the three samples. However, defatted quinoa had lower slowly digestible starch content than NDQ, being the lowest value for DQ-SCCO2 sample. The work confirms the feasibility of using DQ-SCCO2 as a raw material in food applications, free of solvent residues, and with a technological quality superior to that obtained by extraction with organic solvents.

Improved Postharvest Quality of Cold Stored Blueberry by Edible Coating Based on Composite Gum Arabic/Roselle Extract Abstract The present work aimed at evaluating the efficacy of gum Arabic–based edible coating enriched with red and white roselle extracts, on the postharvest quality of blueberry fruits during storage at 4 ± 0.5 °C. Physicochemical, phytochemicals, antioxidant capability, decay percent, and microbiological analyses of coated and uncoated blueberries were performed. The change rates of polyphenol oxidase (PPO) and guaiacol peroxidase (POD) activity were also measured. The coatings (gum Arabic with or without roselle extract) inhibited the growth of microbes (yeast and mesophilic aerobic bacteria) and enzyme activities (POD and PPO) of blueberries, reduced the degradation of anthocyanins and total phenolic as well as the weight loss and decay, and improved the firmness of blueberries. In comparison with gum Arabic coating, the gum Arabic enriched with roselle extract coating showed better performance on reducing microbes, enzyme activities, and anthocyanins degradation while enhancing the total phenolic content and decreasing the decay percentage. No significant differences were observed between the coated and uncoated blueberries in terms of their antioxidant capacities and pH values (p > 0.05). In conclusion, the combination of gum Arabic and roselle extract as edible coating materials can be used to conserve the quality of blueberry.

Online Low-field Nuclear Magnetic Resonance (LF-NMR) and Magnetic Resonance Imaging (MRI) for Food Quality Optimization in Food Processing Abstract Low-field nuclear magnetic resonance (LF-NMR) and magnetic resonance imaging (MRI) have been accepted widely as a non-destructive analytical technique in food processing technology due to their sensitivity, non-invasiveness, rapidness, and cost-effectiveness. Moreover, the ability to provide real-time information on products during and after processing has been linked to the use of these analytical techniques. Timely information on quality parameters in food processing provided by online monitoring using LF-NMR and MRI may increase the quality of the product, improve operation process, and enhance production economy in food field. In this review, the use of online LF-NMR and MRI in food processing techniques, such as drying, brining and freezing, frying, fermentation, and internal quality analysis, is explored. Limitations and need for further development are outlined.