The effect of thermal treatments including sous-vide, blast freezing and their combinations on beef tenderness of M. semitendinosus steaks targeted at elderly consumers

Beef is nutritionally well-suited to elderly people but it has a relatively tough texture compared with many other foods. Strategies to develop meat products requiring reduced mastication effort could potentially enhance intake, and therefore nutritional status, in, the elderly. Cooking steaks 'sous-vide' enhances tenderness and increase retention of natural juices. Freezing may also have a beneficial effect on tenderness due to cellular disruption through ice crystal formation. Five thermal treatments, including sous-vide cooking at 60 degrees C for 270 min (SV), cooking in a circulating water bath until core temperature of 70 degrees C was achieved (C), freezing at -20 degrees C for 48 h (F) and their combinations (i.e. SV, SVC, FC, FSV & FSVC) and a control, were applied to M. semitendinosus beef steaks. SV and FSVC significantly (P < 0.05) reduced WBSF values from 32.97 N (control) to 27.80 N and 26.57 N respectively. SV alone and FSV significantly reduced (P < 0.05) TPA hardness and chewiness when compared with controls. These two treatments had acceptable colour characteristics and could potentially be visually appealing for elderly consumers, due to their reduced visual brownness compared to controls. Results suggest that beef steaks tenderized through SV and FSV treatments represent promising options for inclusion in texture-modified diets targeted to older adults. (C) 2016 Elsevier Ltd. All rights reserved.