Characterization of Biodegradable Food Contact Materials under Gamma-Radiation Treatment.

Radiation is an example of one of the techniques used for pasteurization and sterilization in various packaging systems. There is a high demand for the evaluation of the possible degradation of new composites, especially based on natural raw materials. The results of experimental research that evaluated the impact of radiation technology on biodegradable and compostable packaging materials up to 40 kGy have been presented. Two commercially available flexible composite films based on aliphatic-aromatic copolyesters (AA) were selected for the study, including one film with chitosan and starch (AA-CH-S) and the other with thermoplastic starch (AA-S). The materials were subjected to the influence of ionizing radiation from 10 to 40 kGy and then tests were carried out to check their usability as packaging material for the food industry. The results showed that the mechanical properties of AA-S films improved due to the radiation-induced cross-linking processes, while in the case of AA-CH-S films, a considerable decrease in the elongation at break was observed. The results also showed a decrease in the WVTR in the case of AA-S and no changes in barrier properties in the case of AA-CH-S. Both materials revealed no changes in the odor analyzed by sensory analysis. In the case of the AA-S films, the higher the radiation dose, the faster the biodegradation rate. In the case of the AA-CH-S film, the radiation did not affect biodegradation. The performed research enables the evaluation of the materials intended for direct contact with food. AA-CH-S was associated with unsatisfactory parameters (exceeding the overall migration limit and revealing color change during storage) while AA-S showed compliance at the level of tests carried out. The study showed that the AA-CH-S composite did not show a synergistic effect due to the presence of chitosan.

Characterization and Classification of Direct and Commercial Strawberry Beverages Using Absorbance-Transmission and Fluorescence Excitation-Emission Matrix Technique.

The subject of this study was to characterize the absorption and fluorescence spectra of various types of strawberry beverages and to test the possibility of distinguishing between direct juices and pasteurized commercial products on the basis of their spectral properties. An absorbance and transmission excitation-emission matrix (A-TEEMTM) technique was used for the acquisition of spectra. The obtained spectra were analyzed using chemometric methods. The principal component analysis (PCA) revealed differences in both the absorption spectra and excitation-emission matrices (EEMs) of two groups of juices. The parallel factor analysis (PARAFAC) enabled the extraction and characterization of excitation and emission profiles and the relative contribution of four fluorescent components of juices, which were related to various groups of polyphenols and nonenzymatic browning products. Partial least squares-discriminant analysis (PLS-DA) models enabled 100% correct class assignment using the absorption spectra in the visible region, unfolded EEMs, and set of emission spectra with excitation at wavelengths of 275, 305, and 365 nm. The analysis of variable importance in projection (VIP) suggested that the polyphenols and nonenzymatic browning products may contribute significantly to the differentiation of commercial and direct juices. The results of the research may contribute to the development of fast methods to test the quality and authenticity of direct and processed strawberry juices.

Controlled fermentation of curly kale juice with the use of autochthonous starter cultures.

The aim of this paper was to evaluate the influence of different indigenous lactic acid bacteria isolates - as a single culture or bacterial consortium - on the functional and physicochemical properties of fermented curly kale juice. All tested variants exhibited good growth parameters, manifested by efficient pH lowering, increases in acidity, and fructose and glucose metabolism, as well as a significant inhibition of pathogens. A slight increase in total phenolic content was observed, while antioxidant activity remained unchanged. L. sakei and MIX A were associated with an increase in riboflavin and pyridoxine content, while L. plantarum only contributed to an increase in vitamin B6 content. Bioconversion of individual phenolic compounds, carotenoids, and glucosinolates strongly depended on the strain-specific metabolism. In the process, the levels of ferulic acid and other hydroxycinnamic acids were maintained, while the content of 9-cis lutein increased. Considering presented results and our previous research regarding probiotic features of LAB strains, among tested starter cultures - L. plantarum seemed to possess the best characteristics as a potential starter culture for controlled fermentation of curly kale juice.

Spontaneously fermented curly kale juice: Microbiological quality, nutritional composition, antioxidant, and antimicrobial properties.

Nondairy fermented products, such as fruit and vegetable juices, are gaining popularity among consumers worldwide for health-related and economic reasons. The purpose of this study was to determine the changes in microbiological quality; antimicrobial and antioxidant activity; and phenolic, vitamin C, minerals, and cadmium content occurring during spontaneous fermentation of curly kale juice. The fermentation process contributed to a significant growth of lactic acid bacteria, enterococci, and yeasts, while no pathogens of Escherichia coli and Salmonella spp. were observed. The antimicrobial properties of the obtained juice improved during fermentation for all indicator microorganisms. Total phenolic content and antioxidant activity increased from 48 to 116 mg gallic acid equivalent/100 mL and from 4.5 to 6.8 mM Trolox/100 mL, respectively, while the content of vitamin C decreased. The results indicated that 100 mL of juice provided a significant contribution to the recommended mineral intake. Moreover, the content of heavy metal Cd was within acceptable limit (6 µg/kg). Overall, our findings indicate that fermented curly kale juice may become popular in the functional food sector, especially among vegetarians and consumers with lactose intolerance or allergy to milk proteins. PRACTICAL APPLICATION: As the market for fermented fruit and vegetable products grows, new plant materials rich in biologically active compounds are being sought. Considering the high demand for sauerkraut, the fermentation of other cruciferous vegetables seems interesting. One example is curly kale, which has been classified as "superfood" due to its numerous beneficial health properties, such as strong antioxidant activity, high vitamins, and minerals content. In addition, a market niche exists due to a lack of fermented green curly kale products on the market, making our study particularly relevant.

Factors Influencing Consumers' Perceptions of Food: A Study of Apple Juice Using Sensory and Visual Attention Methods.

The aim of this study was to evaluate the influence of intrinsic product characteristics and extrinsic packaging-related factors on the food quality perception. Sensory and visual attention methods were used to study how consumers perceive the quality of commercial apple juices from four product categories: clear juices from concentrate, cloudy juices from concentrate, pasteurized cloudy juices not from concentrate, and fresh juices. Laboratory tests included the assessment of sensory liking in blind and informed conditions and expected liking based on packages only. The results showed that brand and package information have a large impact on consumers' sensory perceptions and generate high sensory expectations. An innovative visual attention tracking technique was used in online experiments to identify packages and label areas on individual packages, which attracted consumer attention. During an online shelf test, consumers mostly focused on not from concentrate juices from local producers, which were perceived as more natural, healthy, and expensive than juices reconstituted from concentrate. When individual labels were analyzed, consumers predominantly focused on nutritional data, brand name, and information about the type of product. The present results confirm a large impact of information and visual stimuli related to packaging on product perception.

The Influence of Packaging on Cosmetic Emulsion during Storage Assessed by FT-NIR Spectroscopy and Color Measurements.

FT-NIR spectroscopy and color measurements were applied to evaluate the influence of packaging on cosmetic cream stored at room and refrigerated conditions. Commercial cosmetic cream was stored for 2 and 4 mo in five containers intended for cosmetics: aluminum jar with polypropylene thermos (Al/PP), acrylic jar with polypropylene thermos (Ac/PP), glass (G) jar, polypropylene (PP) jar, and styrene acrylonitrile (SAN) jars. Principal component analysis (PCA) of the FT-NIR spectra showed the effect of time on tested samples stored in all applied packagings; separate groups were formed by fresh samples and samples stored for 2 and 4 mo. The changes in samples stored in the cold for 2 mo were similar for all applied packagings as compared with fresh samples, although samples stored in SAN jars formed a separate group. After 4 mo, a separate group was formed by samples stored in G jars. For samples stored at room temperature, the influence of packaging material on cosmetic emulsion was clearly visible; four separate groups (Al/PP with PP, Ac/PP, G, and SAN) were created by samples stored for 4 mo. Using partial least squares (PLS1) regression, it was found that the FT-NIR spectra of tested samples correlated with their lightness L*, a* parameter, and total color difference ΔE * ab . FT-NIR spectroscopy is a rapid technique which could be useful to make the best choice of packaging for cosmetics protecting the original quality of products during long-term storage.

Explorative study of apple juice fluorescence in relation to antioxidant properties.

Total fluorescence spectra (excitation-emission matrices, EEM) were recorded for a series of commercial apple juices, including clear and cloudy juices produced from concentrate, cloudy juices that were not from concentrate, and freshly squeezed juices. An exploratory study of the spectra with parallel factor analysis (PARAFAC) revealed three groups of fluorophores with different emission properties, and these properties were characterized by excitation/emission maxima at 270/315nm, (310, 370)/455nm, and 430/(550, 680)nm, respectively. A regression analysis of the total fluorescence spectra arranged into three-way arrays using N-way partial least squares regression methods (NPLS1 and NPLS2) and an analysis of the unfolded spectra by partial least squares methods (PLS1 and PLS2) revealed quantitative relations between the fluorescence and antioxidant properties of juices. The best models for the total phenolic contents and total antioxidant capacities were obtained by applying the NPLS1 method to the EEM. The model parameters were as follows: R(2)CV=0.802, RPD=2.3 for the total phenolic content and R(2)CV=0.808 and RPD=2.3 for the total antioxidant capacity. These results show the potential use of fluorescence spectroscopy for screening apple juices for their antioxidant properties.