Freezing of meat 139 Table 7.1 relationship between freezing rate of beef M rsi and weight loss during freezing. thawing and cooking Freezing rate(cmh Weight loss during Freezing Tha Cookin Control 0.22 1.15 3747 0.63 003 ource: Petrovic et al. 1993. Table 7.2 Relationship between freezing rate of beef M. zing rate Texture Tenderness juicines Control 7.0 0.22 7.0 6.0 0.39 777 000 5 7.0 .0 8.5 5.66 7.0 7.3 Source: Petrovic et al.. 1993 Texture: 1=extremely tough, 7= extremely fine. Tenderness: 1 =extremely hard, 9= extremely tender Juiciness: 1 =extremely dry, 9= extremely juicy. small samples of mutton muscle ( Sacks et al, 1993). In all cases, drip loss after 2.5 months was at least double the percentage measured after 48h (Table 7.3). After 2.5 months, drip loss from samples frozen using cryogen ics was >2%less than in those using air freezing. The most recent comparison(Sundsten et aL., 2001)revealed some com- mercial advantages of fast freezing, but no quality advantages. The studies ompared three different freezing methods, spiral freezing(SF), cryogenic freezing(liquid nitrogen, LN) and impingement freezing(IF). The times equired to freeze a 10mm thick 80g hamburger from +4 C to -18C in the sf,in and if were 22 min, 5min 30s and 2min 40s, respectively. The uthors state that dehydration was significantly higher for hamburgers frozen in SF (1.2%)compared to LN (0.4%)and IF(0.4%). No significantsmall samples of mutton muscle (Sacks et al., 1993). In all cases, drip loss after 2.5 months was at least double the percentage measured after 48 h (Table 7.3). After 2.5 months, drip loss from samples frozen using cryogen￾ics was >2% less than in those using air freezing. The most recent comparison (Sundsten et al., 2001) revealed some com￾mercial advantages of fast freezing, but no quality advantages. The studies compared three different freezing methods, spiral freezing (SF), cryogenic freezing (liquid nitrogen, LN) and impingement freezing (IF). The times required to freeze a 10mm thick 80g hamburger from +4 °C to -18 °C in the SF, LN and IF were 22 min, 5 min 30 s and 2 min 40 s, respectively. The authors state that dehydration was significantly higher for hamburgers frozen in SF (1.2%) compared to LN (0.4%) and IF (0.4%). No significant Freezing of meat 139 Table 7.1 Relationship between freezing rate of beef M. longissimus dorsi and weight loss during freezing, thawing and cooking Freezing rate (cm h-1 ) % Weight loss during Freezing Thawing Cooking Control – – 36.32 0.22 2.83 0.78 38.41 0.39 2.58 0.72 38.00 3.33 1.15 1.21 37.47 3.95 1.05 0.18 37.24 4.92 0.87 0.10 37.15 5.66 0.63 0.03 37.14 Source: Petrovic et al., 1993. Table 7.2 Relationship between freezing rate of beef M. longissimus dorsi and texture Freezing rate Texture Tenderness Juiciness (cm h-1 ) Control 7.0 6.8 7.0 0.22 7.0 6.0 6.7 0.39 7.0 6.5 7.0 3.33 7.0 7.5 7.5 3.95 7.0 8.0 8.0 4.92 7.0 8.5 8.5 5.66 6.0 7.0 7.3 Source: Petrovic et al., 1993. Texture: 1 = extremely tough, 7 = extremely fine. Tenderness: 1 = extremely hard, 9 = extremely tender. Juiciness: 1 = extremely dry, 9 = extremely juicy