Search

(1) Background: The authenticity of eggs in relation to the housing system of laying hens is susceptible to food fraud due to the potential for egg mislabeling. (2) Methods: A total of 4188 egg yolks, obtained from four different breeds of laying hens housed in colony cage, barn, free-range, and organic systems, were analyzed using 1H NMR spectroscopy. The data of the resulting 1H NMR spectra were used for different machine learning methods to build classification models for the four housing systems. (3) Results: The comparison of the seven computed models showed that the support vector machine (SVM) model gave the best results with a cross-validation accuracy of 98.5%. The test of classification models with eggs from supermarkets showed that only a maximum of 62.8% of samples were classified according to the housing system labeled on the eggs. (4) Conclusion: The classification models developed in this study included the largest sample size compared to the literature. The SVM model is most suitable for evaluating 1H NMR data in terms of the hen housing system. The test with supermarket samples showed that more authentic samples to analyze influencing factors such as breed, feeding, and housing changes are required.

Ohmic heating (OH) is an alternative sustainable heating technology that has demonstrated its potential to modify protein structures and aggregates. Furthermore, certain protein aggregates, namely amyloid fibrils (AF), are associated with an enhanced protein functionality, such as gelation. This study evaluates how Ohmic heating (OH) influences the formation of AF structures from ovalbumin source under two electric field strength levels, 8.5 to 10.5 and 24.0–31.0 V/cm, respectively. Hence, AF aggregate formation was assessed over holding times ranging from 30 to 1200 sunder various environmental conditions (3.45 and 67.95 mM NaCl, 80, 85 and 90 °C, pH = 7). AF were formed under all conditions. SDS-PAGE revealed that OH had a higher tendency to preserve native ovalbumin molecules. Furthermore, Congo Red and Thioflavin T stainings indicated that OH reduces the amount of AF structures. This finding was supported by FTIR measurements, which showed OH samples to contain lower amounts of beta-sheets. Field flow fractioning revealed smaller-sized aggregates or aggregate clusters occurred after OH treatment. In contrast, prolonged holding time or higher treatment temperatures increased ThT fluorescence, beta-sheet structures and aggregate as well as cluster sizes. Ionic strength was found to dominate the effects of electric field strength under different environmental conditions.

Grapevine roots, as a side-stream of a vineyard, are a sustainable resource for the recovery of oligomeric stilbenoids, such as the bioactive r-viniferin. The aim of this study is to evaluate an in silico-supported method, based on the Conductor-like Screening Model for Real Solvents (COSMO-RS), for selection of environmentally friendly natural deep eutectic solvents (NADES) with regard to the extraction of grapevine roots. The most suitable NADES system for ultrasonic-assisted extraction of r-viniferin was choline chloride/1,2-propanediol. The optimal extraction parameters for r-viniferin were determined using single-factor experiments as follows: choline chloride/1,2-propanediol 1/2 mol/mol, 10 wt% H2O, biomass/NADES ratio 1/10 g/g, and 10 min extraction time. Under optimized conditions, the extraction yield of r-viniferin from grapevine roots reached 76% of the total r-viniferin content. Regarding stability, stilbenoids in choline chloride/1,2-propanediol remained stable during 128 days of storage at ambient temperature. However, fructose/lactic acid-based NADES were observed to degrade stilbenoids; therefore, the removal of the NADES will be of interest, with a suitable method implemented using Amberlite® XAD-16N resin. As green solvents, the NADES have been used as effective and environmentally friendly extractants of stilbenoid-containing extracts from grapevine roots for potential applications in the cosmetic and pharmaceutical industry or as nutraceuticals in the food industry.

Grapevine canes are an important source of bioactive compounds, such as stilbenoids. This study aimed to evaluate an in silico method, based on the Conductor-like Screening Model for Real Solvents (COSMO-RS) to isolate stilbenoids from a grapevine cane extract by offline heart-cut high-performance countercurrent chromatography (HPCCC). For the following extraction of resveratrol and ε-viniferin from grapevine canes, natural deep eutectic solvents (NADES) were used as an environmentally friendly alternative to the traditionally used organic solvents. In order to evaluate a variety of combinations of hydrogen bond acceptors (HBAs) and hydrogen bond donors (HBDs) for the targeted extraction of stilbenoids, COSMO-RS was applied. In particular, ultrasonic-assisted extraction using a solvent mixture of choline chloride/1,2-propanediol leads to higher extraction yields of resveratrol and ε-viniferin. COSMO-RS calculations for NADES extraction combined with HPCCC biphasic solvent system calculations are a powerful combination for the sustainable extraction, recovery, and isolation of natural products. This in silico-supported workflow enables the reduction of preliminary experimental tests required for the extraction and isolation of natural compounds.

In this work we report the new technical feasibility of combining a large-scale screw pressing facility with an industrial-scale pulsed electric field (PEF) system for a great increase in the yields of plant juice and crude protein extracted from freshly harvested blends of perennial ryegrass (Lolium perenne) (70%) and white clover (30%). A disk separator has been successfully utilized for continuous separation of 400 L of raw juice and successive protein precipitated at pH 5.0 and 60 °C. The yields of pressed juice and crude protein were increased by around 25% and 31%, respectively. The crude protein content reached 37.3 g/100 g in dry matter. In addition to the crude protein, the precipitated sediment contained minerals like Ca, K, Na, Mg and P, which are essential for health and promisingly interesting for future applications such as food alternatives. Microbial status, chemical compositions, macromolecular sizes and fat-protein microstructures of the samples collected at different process steps were explored, which allows for a better understanding of pilot-scale extraction processes and optimization. This study indicated a great potential for protein extraction from green biomass and for future food applications.

(1) Background: The selection of raw material and the postmortem processing of beef influence its quality, such as taste. In this study, the metabolome of beef from cows and heifers is examined for differences during aging. (2) Methods: Thirty strip loins from eight heifers and seven cows (breed code: 01–SBT) were cut into ten pieces and aged for 0, 7, 14, 21 and 28 days. Samples from the left strip loins were wet-aged in vacuum, while samples from right strip loins were dry-aged at 2 °C and 75% relative humidity. The beef samples were extracted with methanol–chloroform–water, and the polar fraction was used for 1H NMR analysis. (3) Results: The PCA and OPLS-DA showed that the metabolome of cows and heifers varied. Eight metabolites revealed significant differences (p < 0.05) in the samples from cows and heifers. The aging time and aging type of beef also affected the metabolome. Twenty-eight and 12 metabolites differed significantly (p < 0.05) with aging time and aging type, respectively. (4) Conclusions: The variations between cows and heifers and aging time affect the metabolome of beef. By comparison, the influence of aging type is present but less pronounced.

The meat industry is typically using a mixture of fresh and frozen meat batters for minced meat production. Our goal was to find the exact threshold for fresh to frozen meat ratio capable of controlling the meat temperature during processing, but without having an adverse effect on the sensory quality of minced pork. To achieve this, the percentage of frozen meat used for the minced pork production was increased from 0% (control) to 50% (maximum) in 10% increments. To keep the minced meat temperature in control and make the processing resistant to fat smearing, the addition of 30% of frozen meat to the meat batter is sufficient. The soluble protein content, instrumental cutting force, and the sensory perceived firmness, juiciness, and inner cohesion were not affected by the addition of frozen meat. However, it has contributed to a significant increase of the drip loss and the amount of non-intact cells (ANIC). With the addition of frozen meat into the minced pork, the compliance to ANIC regulation by the German regulatory authorities is technologically (practically) almost impossible.

Larger processing equipment to produce minced meat could affect its structure due to intensive processing and a high energy intake in the meat mass. To assess if this would result in alterations in the minced meat quality, finely chopped meat (FCM) was added in different concentrations (15, 30, 45, 60, 75, 90, and 100%) to minced meat and quality parameters were analyzed. FCM was used to simulate different intensity of an unintended destruction of meat cells due to various processes. The amount of non-intact cells (ANIC) was determined histologically and furthermore, soluble protein content, water holding capacity, mechanical and sensory texture, and scanning electron and confocal laser scanning microscopy was applied to analyze the meat structure and quality. ANIC indicated that even adding 15% FCM was statistically (p < 0.05) distinguishable from 100% minced meat and 30% FCM had already 50 Vol.-% ANIC. In contrast, the addition of 15% or 30% FCM did not result in significant differences in drip loss of raw and cooked meat as well as mechanical and sensory texture analysis. This study showed that intensive processing might be detectable via ANIC, but that the minced meat quality was not affected.

(1) Background: The authenticity of eggs in relation to the housing system of laying hens is susceptible to food fraud due to the potential for egg mislabeling. (2) Methods: A total of 4188 egg yolks, obtained from four different breeds of laying hens housed in colony cage, barn, free-range, and organic systems, were analyzed using 1H NMR spectroscopy. The data of the resulting 1H NMR spectra were used for different machine learning methods to build classification models for the four housing systems. (3) Results: The comparison of the seven computed models showed that the support vector machine (SVM) model gave the best results with a cross-validation accuracy of 98.5%. The test of classification models with eggs from supermarkets showed that only a maximum of 62.8% of samples were classified according to the housing system labeled on the eggs. (4) Conclusion: The classification models developed in this study included the largest sample size compared to the literature. The SVM model is most suitable for evaluating 1H NMR data in terms of the hen housing system. The test with supermarket samples showed that more authentic samples to analyze influencing factors such as breed, feeding, and housing changes are required. [ABSTRACT FROM AUTHOR]

The purpose of this review is to provide an overview of the current knowledge about proteomic and metabolic changes in beef, the microbiological alteration postmortem and during aging, and observe the influence on beef quality parameters, such as tenderness, taste and flavor. This review will also focus on the different aging types (wet- and dry-aging), the aging or postmortem time of beef and their effect on the proteome and metabolome of beef. The Ca2+ homeostasis and adenosine 5'-triphosphate breakdown are the main reactions in the pre-rigor phase. After rigor mortis, the enzymatic degradation of connective tissues and breakdown of energy metabolism dominate molecular changes in beef. Important metabolic processes leading to the formation of saccharides, nucleotides, organic acids (e.g. lactic acid), creatine and fatty acids are considered in this context as possible flavor precursors or formers of beef flavor and taste. Flavor precursors are substrates for lipid oxidation, Strecker degradation and Maillard reaction during cooking or roasting. The findings presented should serve as a basis for a better understanding of beef aging and its molecular effects and are intended to contribute to meeting the challenges of improving beef quality. [ABSTRACT FROM AUTHOR]

Anthocyanins are often associated with health benefits. They readily degrade during processing and storage but are also dependent on the matrix conditions. This study investigated how strawberry anthocyanins are affected by preservation technologies and a relatively protein-rich kale juice addition during storage. A strawberry–kale mix was compared to a strawberry–water mix (1:2 wt; pH 4), untreated, thermally, pulsed electric fields (PEF) and high-pressure processing (HPP) treated, and evaluated for anthocyanin stability and bioaccessibility during refrigerated storage. The degradation of strawberry anthocyanins during storage followed first-order kinetics and was dependent on the juice system, preservation technology and anthocyanin structure. Generally, the degradation rate was higher for the strawberry–kale mix compared to the strawberry–water mix. The untreated sample showed the highest degradation rate, followed by HPP, PEF and, then thermal. The relative anthocyanin bioaccessibility after gastric digestion was 10% higher for the thermally and PEF treated samples. Anthocyanin bioaccessibility after intestinal digestion was low due to instability at a neutral pH, especially for the strawberry–kale mix, and after thermal treatment. The storage period did not influence the relative bioaccessibility; yet, the absolute content of bioaccessible anthocyanins was decreased after storage. This research further presents that processing and formulation strongly affect the stability and bioaccessibility of anthocyanins during storage.

(1) Background: The selection of raw material and the postmortem processing of beef influence its quality, such as taste. In this study, the metabolome of beef from cows and heifers is examined for differences during aging. (2) Methods: Thirty strip loins from eight heifers and seven cows (breed code: 01–SBT) were cut into ten pieces and aged for 0, 7, 14, 21 and 28 days. Samples from the left strip loins were wet-aged in vacuum, while samples from right strip loins were dry-aged at 2 °C and 75% relative humidity. The beef samples were extracted with methanol–chloroform–water, and the polar fraction was used for 1H NMR analysis. (3) Results: The PCA and OPLS-DA showed that the metabolome of cows and heifers varied. Eight metabolites revealed significant differences (p < 0.05) in the samples from cows and heifers. The aging time and aging type of beef also affected the metabolome. Twenty-eight and 12 metabolites differed significantly (p < 0.05) with aging time and aging type, respectively. (4) Conclusions: The variations between cows and heifers and aging time affect the metabolome of beef. By comparison, the influence of aging type is present but less pronounced. [ABSTRACT FROM AUTHOR]