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Microalgae are considered a promising resource of proteins, lipids, carbohydrates, and other functional biomolecules for food and feed markets. Competitive drying solutions are required to meet future demands for high-quality algal biomass while ensuring proper preservation at reduced costs. Since often used drying methods, such as freeze or spray drying, are energy and time consuming, more sustainable processes remain to be developed. This study tested an indirect and hybrid solar dryer as an alternative to conventional freeze drying of industrially produced Tetraselmis chui and Nannochloropsis oceanica wet paste. The effects of the drying method on biomass quality parameters, including biochemical profiles, functional properties, and microbial safety, were assessed. No significant differences were found between the applied drying technologies for total proteins, carbohydrates, lipids, and fatty acid profiles. On the other hand, some pigments showed significant differences, displaying up to 44.5% higher contents in freeze-dried samples. Minor differences were also registered in the mineral profiles (<10%). Analyses of microbial safety and functional properties of the solar-dried biomass appear adequate for food and feed products. In conclusion, industrial solar drying is a sustainable technology with a high potential to preserve high-quality microalgal biomass for various markets at expected lower costs.

No abstract

Taste as an eating quality factor of beef can be influenced by the selection of the raw material and aging method. The metabolic changes of different breeds during aging were analyzed in wet-aged and dry-aged beef up to 28 days of aging using samples from the M. longissimus thoracis et lumborum of the Simmental and Black-and-White breeds by 1H NMR spectroscopy. Breed affected the metabolome of beef samples before and during the aging of beef. The concentration of 24 of the 30 metabolites differed significantly (P < 0.05) in unaged samples of both breeds. In addition, aging time and aging type of beef samples showed partially different effects on the metabolome caused by the breed. Aging time significantly affected (P < 0.05) 30 metabolites in beef of both breeds. Aspartate, betaine, creatinine, glycine, and niacinamide correlated with aging time only in samples of Black-and-White breed. Five metabolites (carnitine, creatine, inosine 5’ monophosphate, lactic acid and O-acetyl-l-carnitine) varied significantly (P < 0.05) between dry-aged and wet-aged beef of both breeds.

Food authenticity in the field of food dyes can be interpreted as the correctness of the coloring ingredients indicated. The Rapid UV/vis Spectroscopic Dye Authentication Assay (RaSDAY) presented in this work was used to verify the authenticity of water-soluble reddish colorings for food use. RaSDAY includes the processing of samples under different experimental conditions with pH variations and heat exposure. The absorbances measured are analyzed by principal component analysis and a k-nearest neighbors algorithm. As a result, classification of anthocyanins, betalains, and carmine and the detection of Monascus pigments, undeclared artificial food dyes, and reactive textile azo dyes can be performed by utilizing a rapid screening method. In 17 out of 20 samples of coloring food additives that were included in this work, reactive dyes, unpermitted Monascus pigments, and artificial food dyes were detected using the developed method. “Reactive Red 120”, “Reactive Red 195”, and “Reactive Red 198” were identified by subsequent 1H NMR spectroscopy in eight of those samples.