Animal Science Department, University of Nebraska-Lincoln, Lincoln, NE 68583-0908, USA.
J Anim Sci. 2013 Jan;91(1):483-90. doi: 10.2527/jas.2012-5223. Epub 2012 Oct 16.
The objective of this study was to evaluate processing methods for frozen beef subprimals; the effects of freezing and thawing rates on tenderness, sensory properties, and retail display were evaluated. There were 6 treatments: fresh, never frozen 14 d wet aged (14D); fresh, never frozen 21 d wet aged (21D); blast frozen-fast thawed (BF); blast frozen-slow thawed (BS); conventionally frozen-fast thawed (CF); and conventionally frozen-slow thawed (CS). All frozen beef subprimals were aged for 14 d before freezing. Three beef subprimal cuts, rib eye roll (n=90), strip loin (n=90), and top sirloin butt (n=90), were used with 3 replications of 5 samples per treatment per week (total of 9 wk, n=270). Blast freezing occurred by placing spacers between the boxes of meat on pallets at -28°C with high air velocity for 3 to 5 d. Conventional freezing occurred with boxes of meat stacked on pallets and placed in a -28°C freezer with minimal air movement for at least 10 d. Fast thawing of subprimals (to an internal temperature of -1°C to 1°C) occurred by immersion in a circulating water bath (<12°C) for 21 h, and slow thawing of subprimals occurred over a 2-wk period by placing individual subprimals on tables at 0°C. Steaks (2.5 cm thick) were cut from the longissimus thoracis (LT), longissimus lumborum (LL), and gluteus medius (GM) for Warner-Bratzler shear force (WBS), trained sensory evaluation, and retail display. For LL and GM beef steaks, frozen treatments were equal or lower in WBS values to 14D and 21D beef steaks. No differences were detected in WBS among the treatments applied to GM beef steaks (P=0.08). There were no differences in sensory tenderness among the LL, LT, and GM (P>0.05). All LL and LT beef steaks had approximately 4 d to 40% discoloration, and all GM steaks had over 3 d to 40% discoloration. Steaks from the LL and LT began to discolor at about 3 d, and the GM began to discolor after 1 d. For all beef subprimals, purge loss during storage and thawing was significantly greater for the slow-thawed subprimals (P<0.01), and all fast-thawed subprimals were equal or superior to 14D and 21D (P<0.01) in storage and thawing purge. During retail display, the greatest purge loss occurred in fast-thawed treatments (P<0.01). Overall, freezing rate did not affect purge loss, and neither freezing nor thawing rates had significant meaningful effects on WBS, and sensory properties were comparable with fresh, never-frozen subprimals.
本研究旨在评估冷冻牛肉副产物的加工方法；研究了冷冻和解冻速率对嫩度、感官特性和零售展示的影响。共有 6 种处理方式：新鲜、从未冷冻过的 14 天湿式老化（14D）；新鲜、从未冷冻过的 21 天湿式老化（21D）；快速冷冻-快速解冻（BF）；快速冷冻-缓慢解冻（BS）；常规冷冻-快速解冻（CF）和常规冷冻-缓慢解冻（CS）。所有冷冻牛肉副产物在冷冻前均进行 14 天湿式老化。使用了 3 种牛肉副产物切割部位，包括肋眼卷（n=90）、里脊（n=90）和上臀肉（n=90），每个处理组每周有 3 个重复，每个重复有 5 个样本（共 9 周，n=270）。快速冷冻是通过在托盘上的肉箱之间放置间隔物，在 -28°C 下以高空气速度冷冻 3 至 5 天来实现的。常规冷冻是将肉箱堆叠在托盘上，然后将其放置在 -28°C 的冷冻机中，空气流动最小，至少 10 天。副产物的快速解冻（内部温度达到-1°C 至 1°C）是通过在循环水浴（<12°C）中浸泡 21 小时来实现的，而副产物的缓慢解冻是通过将单个副产物放置在 0°C 的桌子上，在 2 周内完成的。从最长肌胸肌（LT）、最长肌腰（LL）和臀中肌（GM）中切出 2.5 厘米厚的牛排，用于测定 Warner-Bratzler 剪切力（WBS）、经过训练的感官评价和零售展示。对于 LL 和 GM 牛肉牛排，冷冻处理的 WBS 值与 14D 和 21D 牛肉牛排相等或更低。GM 牛肉牛排的不同处理方式之间的 WBS 值没有差异（P=0.08）。在 LL、LT 和 GM 之间，感官嫩度没有差异（P>0.05）。所有 LL 和 LT 牛排的颜色变化约为 4 天至 40%，所有 GM 牛排的颜色变化超过 3 天至 40%。LL 和 LT 牛排开始变色约 3 天，GM 牛排在 1 天后开始变色。对于所有牛肉副产物，在储存和解冻过程中，缓慢解冻的副产物的渗出损失明显更大（P<0.01），所有快速解冻的副产物在储存和解冻过程中的渗出损失均与 14D 和 21D（P<0.01）相等或更高。在零售展示过程中，快速解冻处理的渗出损失最大（P<0.01）。总体而言，冷冻速率不会影响渗出损失，冷冻和解冻速率对 WBS 和感官特性均没有显著影响，且与新鲜、从未冷冻过的副产物相当。
