Onopordum platylepis (Murb.) Murb. as a novel source of thistle rennet: First application to the manufacture of traditional Italian raw ewe's milk cheese.

In this study, for the very first time, aqueous extracts obtained from flowers of spontaneously grown or cultivated Onopordum platylepis (Murb.) Murb. thistles were used as coagulating agents for the pilot-scale manufacture of Caciofiore, a traditional Italian raw ewe's milk cheese. Cheese prototypes were compared to control cheeses curdled with a commercial thistle rennet obtained from flowers of Cynara cardunculus L. After 45 days of ripening under controlled conditions, both the experimental and control cheese prototypes were analyzed for: cheese yield, physico-chemical (pH, titratable acidity, aw, proximate composition), morpho-textural (color and texture), and microbiological parameters (viable cell counts and species composition assessed by Illumina sequencing), as well as volatile profile by SPME-GC-MS. Slight variations in titratable acidity, color, and texture were observed among samples. Based on the results overall collected, neither the yield nor the proximate composition was apparently affected by the type of thistle coagulant. However, the experimental cheese prototypes curdled with extracts from flowers of both spontaneous or cultivated thistles showed 10 % higher values of water-soluble nitrogen compared to the control prototypes. On the other hand, these latter showed slightly higher loads of presumptive lactococci, thermophilic cocci, coliforms, and eumycetes, but lower counts of Escherichia coli. No statistically significant differences were revealed by the metataxonomic analysis of the bacterial and fungal biota. Though most volatile organic compounds (VOCs) were consistent among the prototypes, significant variability was observed in the abundance of some key aroma compounds, such as butanoic, hexanoic, and octanoic acids, ethanol, propan-2-ol, isobutyl acetate, 2-methyl butanoic acid, and 3-methyl butanal. However, further investigations are required to attribute these differences to either the type of coagulant or the metabolic activity of the microorganisms occurring in the analyzed cheese samples. The results overall collected support the potential exploitation of O. platylepis as a novel source of thistle coagulant to produce ewe's milk cheeses.

Impact of Refrigerated Storage on Microbial Growth, Color Stability, and pH of Turkey Thigh Muscles.

The quality of poultry meat offered to the consumer depends mainly on the level of hygiene during all stages of its production, storage time, and temperature. This study investigated the effect of refrigerated storage on the microbiological contamination, color, and pH of turkey thigh muscles stored at 1 °C over six days. Microbial growth, including total mesophilic aerobes, presumptive lactic acid bacteria, and Enterobacteriaceae, significantly increased, impacting the meat's sensory attributes and safety. On the 6th day of meat storage, the content of total mesophilic aerobes, presumptive lactic acid bacteria, and Enterobacteriaceae was 1.82 × 107 CFU/g, 1.00 × 104 CFU/g, and 1.87 × 105 CFU/g, respectively. The stability of color was assessed by quantifying the total heme pigments, comparing myoglobin, oxymyoglobin, and metmyoglobin concentrations, analyzing color parameters L*, a*, b*, and the sensory assessment of surface color, showing a decline in total heme pigments, three myoglobin forms, redness (a*) and lightness (L*). In contrast, yellowness (b*) increased. These changes were correlated with the growth of spoilage microorganisms that influenced the meat's pigmentation and pH, with a notable rise in pH associated with microbial metabolization. Based on the conducted research, it was found that the maximum storage time of turkey thigh muscles at a temperature of 1 °C is 4 days. On the 4th day of storage, the total mesophilic aerobe content was 3.5 × 105 CFU/g. This study underscores the critical need for maintaining controlled refrigeration conditions to mitigate spoilage, ensuring food safety, and preserving turkey meat's sensory and nutritional qualities. There is a need for further research to improve turkey meat storage techniques under specific temperature conditions by studying the impact of using varying packaging materials (with different barrier properties) or the application of natural preservatives. Additionally, future studies could focus on evaluating the effectiveness of cold chain management practices to ensure the quality and safety of turkey products during storage. By addressing these research gaps, practitioners and researchers can contribute to developing more efficient and sustainable turkey meat supply chains, which may help mitigate food wastage by safeguarding the quality and safety of the meat.

Effect of plasma-activated water (PAW) soaking on the lipid oxidation of sardine (Sardina pilchardus) fillets.

The efficacy of plasma-activated water (PAW) as a chemical-free and environmentally friendly preservative has been documented for a variety of foods, but the onset of lipid oxidation induced by plasma-reactive species has been less extensively studied. In this work, global indices (peroxide value, UV specific absorbance) and direct analytical determinations of volatile and non-volatile oxidation products were performed on sardine lipids extracted from fish fillets immersed in PAW (treatments) and distilled water (controls) for 10-30 min. Evidence of PAW-induced lipid oxidation was provided by higher UV specific absorbances and higher levels of C5-C9 secondary volatile oxidation products in the treated samples. However, the degree of fatty acid oxidation was not sufficient to cause a significant reduction in nutritionally valuable eicosapentaenoic acid and docosahexaenoic acid. Twelve cholesterol oxidation products (COPs) were identified in the sardine lipids, but no significant differences in total COPs content were found between PAW processed and control samples.

First ATR-FTIR Characterization of Black, Green and White Teas (Camellia sinensis) from European Tea Gardens: A PCA Analysis to Differentiate Leaves from the In-Cup Infusion.

ATR-FTIR (Attenuated Total Reflectance Fourier Transform InfraRed) spectroscopy, combined with chemometric, represents a rapid and reliable approach to obtain information about the macromolecular composition of food and plant materials. With a single measurement, the chemical fingerprint of the analyzed sample is rapidly obtained. Hence, this technique was used for investigating 13 differently processed tea leaves (green, black and white) all grown and processed in European tea gardens, and their vacuum-dried tea brews, prepared using both hot and cold water, to observe how the components differ from tea leaf to the in-cup infusion. Spectra were collected in the 1800-600 cm-1 region and were submitted to Principal Component Analysis (PCA). The comparison of the spectral profiles of leaves and hot and cold infusions of tea from the same country, emphasizes how they differ in relation to the different spectral regions. Differences were also noted among the different countries. Furthermore, the changes observed (e.g., at ~1340 cm-1) due to catechin content, confirm the antioxidant properties of these teas. Overall, this experimental approach could be relevant for rapid analysis of various tea types and could pave the way for the industrial discrimination of teas and of their health properties without the need of time-consuming, lab chemical assays.