Utilisation of a cell‐free extract of lactic acid bacteria entrapped in yeast to enhance flavour development in Cheddar cheese

Abstract

A lactococcal cell‐free extract (CFE) was successfully entrapped in freeze‐dried attenuated yeast. The entrapment process involved passive diffusion of enzymes from the CFE into the yeast during hydration. The entrapped CFE was subsequently added during Cheddar cheese production and its impact on a range of ripening parameters compared to added attenuated yeast or CFE alone. Statistically significant differences were evident for secondary proteolysis, sensory attributes and volatiles, which were related to enhanced enzymatic and metabolic activity from the attenuated yeast and entrapped CFE. This study highlights the potential of attenuated yeast as a vector to augment flavour development in Cheddar cheese.

Microbial cell-free extracts as sources of enzyme activities to be used for enhancement flavor development of ewe milk cheese

“…Compared with CC, all the enzyme activities were higher in the cheeses made with CFE. The highest (P < 0.05) differences were found after 30 d. These findings were in contrast with those reported in other studies, where no significant differences were found when commercial enzymes or CFE were used for cheesemaking (Yarlagadda et al, 2014). Losses of en-zymes in the drained whey (Wilkinson and Kilcawley, 2005) or the inherent instability of such enzymes under cheese ripening environmental conditions (Sheehan et al, 2009) may be the causes for these different behavior.…”

“…This is one of the main prerequisites to successfully use CFE. As recently shown (Nongonierma et al, 2013;Yarlagadda et al, 2014), the gross composition of Cheddar cheese did not vary when CFE from lactic acid bacteria were entrapped in yeasts or encapsulated in liposomes to enhance flavor development. The pH values of all ewe milk cheeses markedly decreased from the curd during manufacture (average value of 6.76) to 1 d of ripening (average value of 5.25), then it slightly varied.…”

“…The highest concentration of FAA was found for the LC cheese (5,029.8 ± 151.0 mg/kg of cheese), which contained the highest level of Phe, Lys, and Pro. Several studies already reported accelerated or increased liberation of FAA when commercial enzymes were used for cheesemaking (Yarlagadda et al, 2014). The concentrations of total FAA attained with cheeses added of CFE approached those found for other Italian ewe milk cheeses ripened for longer times (Coda et al, 2006).…”

“…Branched-chain aldehydes mainly result from the catabolism of FAA (McSweeney and Sousa, 2000) and are associated with pungent, almond, and chemical aromas (Tunick, 2007).Valine, Leu, Ile, Phe, Tyr, Trp, and Met are well known precursors of branched-chain aldehydes, and their levels were particularly abundant when CFE from W. cibaria 1XF5 was used. Secondary alcohols derive from the reduction of methyl ketones, whereas methyl-branched alcohols are synthesized from aldehyde reduction, which are formed from branched FAA or free FA (Yarlagadda et al, 2014). The highest level of alcohols found in the cheese made with CFE from D. hansenii LCF-585 was consistent with the high esterase and iminopeptidase activities.…”

Quality characteristics, chemical composition, and sensory properties of butter from cows on pasture versus indoor feeding systems

“…The order of the presentation of all test samples was randomized to prevent first-order and carryover effects, and all samples were presented in duplicate. The assessors then participated in ranking descriptive analysis (Cavanagh et al, 2014;Yarlagadda et al, 2014;Fellendorf et al, 2016) using the consensus list of sensory descriptors provided to them, which was also measured on a 10-cm line scale. All samples were again presented in duplicate (Stone et al, 2012a).…”