Evaluation of Color and Pigment Changes in Tomato after 1-Methylcyclopropene (1-MCP) Treatment.

The Polar Qualification System (PQS) was applied on hue spectra fingerprinting to describe color changes in tomato during storage. The cultivar 'Pitenza' was harvested at six different maturity stages, and half of the samples were subjected to gaseous 1-methylcyclopropene (1-MCP) treatment. Reference color parameters were recorded with a vision system colorimeter instrument, and the fruit pigment concentration was assessed with the DA-index®. Additionally, acoustic firmness (Stiffness) was measured. All acquired reference parameters were used to grade fruit in the supply chain. The applied 1-MCP treatments were used to control the ripening of climacteric horticultural produce. Both the DA-index® and stiffness values, presented as chlorophyll concentration and acoustic firmness, showed significant differences among maturity stages and treated and control samples and in their kinetics during storage. The machine vision parameter PQS-X was significantly affected by 1-MCP treatment (F = 10.18, p < 0.01), while PQS-Y was primarily affected by storage time (F = 18.18, p < 0.01) and maturity stage (F = 11.15, p < 0.01). A significant correlation was achieved for acoustic firmness with normalized color (r > 0.78) and PQS-Y (r > 0.80), as well as for the DA-index® (r > 0.9). The observed color changes agreed with the reference measurements. The significant statistical effect on the PQS coordinates suggests that hue spectra fingerprinting with this data compression technique is suitable for quality assessment based on color.

Application of Near Infrared Spectroscopy to Monitor the Quality Change of Sour Cherry Stored under Modified Atmosphere Conditions.

Determining and applying 'good' postharvest and quality control practices for otherwise highly sensitive fruits, such as sour cherry, is critical, as they serve as excellent media for a wide variety of microbial contaminants. The objective of this research was to report two series of experiments on the modified atmosphere storage (MAP) of sour cherries (Prunus cerasus L. var. Kántorjánosi, Újfehértói fürtös). Firstly, the significant effect of different washing pre-treatments on various quality indices was examined (i.e., headspace gas composition, weight loss, decay rate, color, firmness, soluble solid content, total plate count) in MAP-packed fruits. Subsequently, the applicability of near infrared (NIR) spectroscopy combined with chemometrics was investigated to detect the effect of various storage conditions (packed as control or MAP, stored at 3 or 5 °C) on sour cherries of different perceived ripeness. Significant differences were found for oxygen concentration when two perforations were applied on the packages of 'Kántorjánosi' (p < 0.01); weight loss when 'Kánorjánosi' (p < 0.001) and 'Újfehértói fürtös' (p < 0.01) were packed in MAP; SSC when 'Újfehértói fürtös' samples were ozone-treated (p < 0.05); and total plate count when 'Kántorjánosi' samples were ozone-treated (p < 0.01). The difference spectra reflected the high variability in the samples, and the detectable effects of different packaging. Based on the investigations with the soft independent modelling of class analogies (SIMCA), different packaging and storage resulted in significant differences in most of the cases even on the first storage day, which in many cases increased by the end of storage. The soft independent modelling of class analogies proved to be suitable for classification with apparent error rates between 0 and 0.5 during prediction regardless of ripeness. The research findings suggest the further correlation of NIR spectroscopic and reference parameters to support postharvest handling and fast quality control.

Origin Identification of Hungarian Honey Using Melissopalynology, Physicochemical Analysis, and Near Infrared Spectroscopy.

The objective of the study was to check the authenticity of Hungarian honey using physicochemical analysis, near infrared spectroscopy, and melissopalynology. In the study, 87 samples from different botanical origins such as acacia, bastard indigo, rape, sunflower, linden, honeydew, milkweed, and sweet chestnut were collected. The samples were analyzed by physicochemical methods (pH, electrical conductivity, and moisture), melissopalynology (300 pollen grains counted), and near infrared spectroscopy (NIRS:740-1700 nm). During the evaluation of the data PCA-LDA models were built for the classification of different botanical and geographical origins, using the methods separately, and in combination (low-level data fusion). PC number optimization and external validation were applied for all the models. Botanical origin classification models were >90% and >55% accurate in the case of the pollen and NIR methods. Improved results were obtained with the combination of the physicochemical, melissopalynology, and NIRS techniques, which provided >99% and >81% accuracy for botanical and geographical origin classification models, respectively. The combination of these methods could be a promising tool for origin identification of honey.

Classification of Bee Pollen and Prediction of Sensory and Colorimetric Attributes-A Sensometric Fusion Approach by e-Nose, e-Tongue and NIR.

The chemical composition of bee pollens differs greatly and depends primarily on the botanical origin of the product. Therefore, it is a crucially important task to discriminate pollens of different plant species. In our work, we aim to determine the applicability of microscopic pollen analysis, spectral colour measurement, sensory, NIR spectroscopy, e-nose and e-tongue methods for the classification of bee pollen of five different botanical origins. Chemometric methods (PCA, LDA) were used to classify bee pollen loads by analysing the statistical pattern of the samples and to determine the independent and combined effects of the above-mentioned methods. The results of the microscopic analysis identified 100% of sunflower, red clover, rapeseed and two polyfloral pollens mainly containing lakeshore bulrush and spiny plumeless thistle. The colour profiles of the samples were different for the five different samples. E-nose and NIR provided 100% classification accuracy, while e-tongue > 94% classification accuracy for the botanical origin identification using LDA. Partial least square regression (PLS) results built to regress on the sensory and spectral colour attributes using the fused data of NIR spectroscopy, e-nose and e-tongue showed higher than 0.8 R2 during the validation except for one attribute, which was much higher compared to the independent models built for instruments.

Detection and Quantification of Tomato Paste Adulteration Using Conventional and Rapid Analytical Methods.

Tomato, and its concentrate are important food ingredients with outstanding gastronomic and industrial importance due to their unique organoleptic, dietary, and compositional properties. Various forms of food adulteration are often suspected in the different tomato-based products causing major economic and sometimes even health problems for the farmers, food industry and consumers. Near infrared (NIR) spectroscopy and electronic tongue (e-tongue) have been lauded as advanced, high sensitivity techniques for quality control. The aim of the present research was to detect and predict relatively low concentration of adulterants, such as paprika seed and corn starch (0.5, 1, 2, 5, 10%), sucrose and salt (0.5, 1, 2, 5%), in tomato paste using conventional (soluble solid content, consistency) and advanced analytical techniques (NIR spectroscopy, e-tongue). The results obtained with the conventional methods were analyzed with univariate statistics (ANOVA), while the data obtained with advanced analytical methods were analyzed with multivariate methods (Principal component analysis (PCA), linear discriminant analysis (LDA), partial least squares regression (PLSR). The conventional methods were only able to detect adulteration at higher concentrations (5-10%). For NIRS and e-tongue, good accuracies were obtained, even in identifying minimal adulterant concentrations (0.5%). Comparatively, NIR spectroscopy proved to be easier to implement and more accurate during our evaluations, when the adulterant contents were estimated with R2 above 0.96 and root mean square error (RMSE) below 1%.

Effect of Two-Step Sous Vide Cooking and Storage on Microbiological and Oxidative Stability of Chicken Breast.

A two-step sous vide method, which included a low temperature initial stage, was shown to improve texture parameters, increase the solubility of proteins, and decrease the cook loss in chicken breasts. The current work was designed to determine the effect of two-step sous vide and subsequent storage on the microbiological and oxidative stability of chicken breasts. Inoculated chicken breasts were vacuum packaged and cooked at two temperatures, 50 °C and 60 °C, combined in different ratios of the same total cooking time (120 min), and then stored for 21 days at 4 °C, 10 °C, and -20 °C, and compared with the one-step temperature treatment (60 °C for 120 min). One-step sous vide treatment resulted in the total inactivation of Enterococcus faecalis NCAIM B. 01312. Meanwhile, the two-step sous vide treatments resulted in a higher than 3 log reduction in Enterococcus faecalis NCAIM B. 01312, reaching the target pasteurization performance criterion of sous vide for poultry meat. Lipid oxidation and the odor of all chicken breasts remained acceptable for 21 days of storage at 4 °C and -20 °C. Conversely, all chicken breasts had higher lipid oxidation rates and odor after 21 days of storage at 10 °C. Two-step-sous-vide-treated chicken breasts were found to be microbiologically stable regarding Enterococcus faecalis NCAIM B. 01312 and total mesophilic aerobic counts during 21 days of storage at 4 °C and -20 °C, in contrast with those stored at 10 °C. It can be concluded that two-step-sous-vide-cooked chicken breasts had acceptable oxidative and microbiological stability during chilled and frozen storage, similar to one-step sous vide ones. These outcomes highlight that two-step heat treatment can be used as an alternative cooking method to improve the quality properties without compromising the storage life of chicken breasts.

Comparison of techno-functional and sensory properties of sponge cakes made with egg powder and different quality of powdered blood products for substituting egg allergen and developing functional food.

Animal blood is a valuable resource, which is usually not utilized in a value-added way by the industry like other animal by-products, even though it has plenty of benefits in terms of sustainability and human health, particularly against iron deficiency anemia. Animal blood is perfectly suitable for providing special functions, which are necessary for functional foods, and improving techno-functional properties based on the previous reports published in the literature. In this paper, egg powder was substituted by powdered animal blood products (whole blood powder, blood plasma powder, and hemoglobin powder) in sponge cake. Techno-functional and sensory properties (texture by texture profile analysis and three-point breaking test, water activity, dry matter content, and color) were instrumentally measured and then a sensory evaluation was carried out by unskilled panelists. Quality characteristics (texture, color, and dry matter content) were daily measured on the day of baking and then every 24 h for 3 additional days because freshly baked cakes are usually consumed within 3 days. Based on the results, powdered blood products are suitable for substituting the egg powder in sponge cakes and developing functional foods. Blood powders can increase the hardness, chewiness, and breaking force of cakes, giving them the ability to be stuffed with more fillings and molded into special shapes without compromising on the sensory characteristics. They can also increase the intensity of the cocoa flavor, which results in a richer, darker color without deceiving the consumers.