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Lactic acid bacteria (LAB) are applied in the food industry as fermentation agents for a variety of products. Cheese whey (CW) and second cheese whey (SCW) are the two main by-products of cheese production, and can be reused for biotechnological purposes. In this context, this review aims to summarise literature on the use of CW and SCW as culture media for the growth of LAB, as cryoprotectants for freeze-drying and as encapsulating agents for the spray-drying of these microorganisms. CW contains several nutrients that are reported to enhance the growth of LAB. As for SCW, research shows that it has potential to be applied as culture medium, although bacterial growth remains at least one or two log orders lower than CW. Regarding freeze-drying and spray-drying, reports indicate that whey-based cryoprotectants and CW as encapsulating agent offer significant protection from the stressful conditions employed in these processes. [ABSTRACT FROM AUTHOR]

This work aimed to validate a method for the quantification of free amino acids in cheese whey protein concentrate and cheese whey protein hydrolysate via gas chromatography coupled with mass spectrometry (GC–MS). For this, free amino acid analysis was carried out with deproteinisation, where the efficiencies of acetonitrile and trichloroacetic acid were compared, prior to derivatisation with N-methyl-N-(tert-butyldimethylsilyl)trifluoroacetamide before GC–MS analysis. The results demonstrated that using trichloroacetic acid enabled the determination of 13 free amino acids (l -alanine, l -valine, l -leucine, l -isoleucine, l -proline, l -methionine, l -serine, l -phenylalanine, l -aspartic acid, l -glutamic acid, l -lysine, l -tyrosine, and l -cystine) in cheese whey protein concentrate and hydrolysate. The method was validated in terms of recovery (85–105%), limits of detection (0.03–0.77 μg mL−1), and limits of quantification (0.09–2.56 μg mL−1). This GC–MS methodology can be used in food laboratories for the quantification of some free amino acids, including branched-chain amino acids, in solid dairy products. [ABSTRACT FROM AUTHOR]