Lowfat ground beef patties (10-11% fat), formulated with 10% water, 0.5% salt and 1-4% whey protein concentrate (WPC), were evaluated for cooking characteristics and compared with controls of higher fat content. A reduction in the fat level from 22 to 11% improved all cooking parameters with respect to better cooking yield (p < 0.01) and fat retention (p < 0.05), increased cooked moisture content (p < 0.05) as well as reduced shrinkage (p < 0.05). Texture profile analysis (TPA) showed an increase in chewiness for low fat samples over the high fat control, while hardness and springiness remained unaffected Adding 10% water to the lowfat meat did not change the cooking characteristics, except for a further increase in cooked moisture content (p < 0.05) and an increase in the value for springiness (p < 0.05). Addition of increasing levels of WPC with 10% water to low Sat meat resulted in a linear increase (p < 0.05) in cooked yield with a linear decrease (p < 0.05) in shrinkage. The 4% WPC level produced the highest cooking yield (125% of the high fat control) and the least shrinkage (49% of the high fat control). Sensory analysis showed the 4% WPC level to be preferred over lower levels with respect to juiciness and overall acceptability. Addition of 0.3% of texture-modifying additives showed that calcium chloride and hydroxypropylmethylcellulose had a detrimental effect on yield and shrinkage, whereas the effect of tripolyphosphate (TPP) was positive (p < 0.05). Perception of juiciness and overall acceptability of formulated lowfat products was significantly better (p < 0.05) with the addition of TPP (0.3%) and lactose (1.2%) to the WPC formulations. Fat levels (11, 18 and 22%) and lactose levels (0.24 and 1.2%) affected volatile components of the beef patties as measured by dynamic head space analysis. Ketones, i.e. 2-butanone, 2-pentanone and 3-hydroxy-2-butanone increased with an increase in fat content from II to 22% fat. Addition of WPC and lactose decreased the relative concentrations of pentane, hexane and heptane. The increase of lactose level in meat was accompanied by an increase in 4,4 diethyl-2-oxetanone and 2-methyl-butanal, two compounds that may originate from non-enzymatic browning of lactose.
