Effect of Trim Level, Cooking Method, and Chop Type on Lipid Retention, Caloric Content, and Cholesterol Level in Cooked Pork

The effect of external fat trim on fat, caloric, and cholesterol content of pork lean was investigated. Paired top-loin chops (TL), rib chops (RC) and blade steaks (BS) were obtained and trimmed free of all subcutaneous fat before (NF) or after (SF) cooking. Cuts were cooked to 71°C by roasting, pan-frying, braising or microwaving. Lean from TL chops having SF contained more fat and calories and similar amounts of cholesterol compared with NF chops, regardless of cooking method. Few differences were observed in fat and caloric content of RC and BS cooked with SF versus NF, perhaps due to seam fat. Eliminating external fat prior to cooking reduced fat and caloric content of pork lean.     

Properties and Utilization of Pork from an Advanced Meat Recovery System

Pork trim from an advanced meat recovery system, referred to as pork trim-finely textured (PTFT), was characterized and compared to 80% lean ground pork (GP) and knife trimmed lean (KT). PTFT (0, 5, 10, 15%) was incorporated into 10% and 20% fat ground pork patties. PTFT had higher total pigment, cholesterol, iron and calcium and lower collagen than GP or KT. Fat content of PTFT was similar to GP and KT. PTFT increased redness and juiciness and decreased hardness, chewiness and cohesiveness of ground pork patties. Addition of up to 15% PTFT caused differences which were perceived as improvements in quality. PTFT can be a replacement for pork trim in ground pork products.     

Marbling, Fat Trim and Doneness Effects on Sensory Attributes, Cooking Loss and Composition of Cooked Beef Steaks

Marbling and fat trim level did not significantly affect sensory attributes of steaks. However, steaks became increasingly tougher and less juicy with increased internal end-point temperature. Cooking losses were greater for steaks with regular trim than those with total trim and increased with degree of doneness. Except for potassium, fat trim levels did not affect mineral content in cooked muscle. Intramuscular fat levels had variable effects on retention of minerals during cooking. Muscle from steaks with slight marbling had higher cholesterol levels than from those with modest marbling, but neither fat trim level nor doneness affected cholesterol content.     

EFFECTS OF FAT TRIM ON THE COMPOSITION OF BEEF RETAIL CUTS – 3. COOKING YIELDS AND FAT RETENTION OF THE SEPARABLE LEAN

Thirty beef carcass sides varying in USDA quality and yield grade were fabricated into various steaks and roasts. The retail cuts were assigned serially to the following treatments: (A) raw, trimmed to 0.6 cm external fat; (b) trimmed to 0.6 cm external fat, cooked; (C) trimmed to 0.0 cm external fat, cooked. The separable lean was analyzed for chemical fat. Regression analyses were used to predict percentage cooking yields and fat retention of the separable lean. Generally, cooking yield was not influenced by USDA grade, but retail cuts cooked with 0.6 cm external fat usually had numerically higher predicted values for cooking yield than cuts trimmed to 0.0 cm before cooking. Braising of thin (< 2.5 cm thick), single-muscle retail cuts decreased the predicted percentage of chemical fat retention of the separable lean. Trimming of retail cuts to 0.0 cm external fat before cooking decreased (compared to the 0.6 cm cuts) the predicted percentage of chemical fat retention of the separable lean as compared to cuts that were trimmed to 0.6 cm.     

EFFECTS OF FAT TRIM ON THE COMPOSITION OF BEEF RETAIL CUTS – 2. FAT AND MOISTURE CONTENT OF THE SEPARABLE LEAN

Thirty beef carcass sides varying in USDA quality and yield grade were fabricated into various steaks and roasts. The retail cuts were assigned serially to the following treatments: (A) raw, trimmed to 0.6 cm external fat; (B) trimmed to 0.6 cm external fat, cooked; (C) trimmed to 0.0 cm external fat, cooked. The 0.0 cm and 0.6 cm, cooked treatments were prepared by appropriate cookery methods, and the separable lean and separable fat were analyzed for chemical fat and moisture content. Regression analyses were used to predict values for the percentage chemical fat and moisture content at each treatment as influenced by marbling and USDA yield grade. Retail cuts that were braised had the lowest (P < 0.05) predicted moisture content of the separable lean, while roasted cuts had the highest (P< 0.05) predicted percentage moisture content of the lean. Trimming retail cuts to 0.0 cm external fat before cooking decreased the predicted percentage chemical fat of the lean as compared to retail cuts trimmed to 0.6 cm before cooking.     

EFFECTS OF FAT TRIM ON THE COMPOSITION OF BEEF RETAIL CUTS – 1. SEPARATE TISSUE COMPONENTS

Thirty beef carcass sides varying in USDA quality and yield grade were fabricated into various steaks and roasts. The retail cuts were assigned serially to the following treatments: (A) raw, trimmed to 0.6 cm external fat; (B) trimmed to 0.6 cm external fat, cooked; (C) trimmed to 0.0 cm external fat, cooked. All cuts were dissected into separable lean, external fat, intermuscular fat, and heavy connective tissue and bone (waste). Regression analyses were used to predict values for the percentage of each dissected entity as influenced by USDA marbling score and yield grade. Dissection data revealed that trimming boneless retail cuts to 0.0 cm before cooking increased percentage separable lean and decreased percentage separable waste and separable fat. It was observed that certain bone-in retail cuts such as arm roasts, blade roasts, and large-end rib roasts had large predicted percentages of intermuscular fat, even if the external fat was trimmed off before cooking.     

EVALUATION OF GROUND PORK AND PORK SAUSAGE CONTAINING DIFFERENT FORMS OF APPLE PRODUCTS

Fat contents of ground pork were altered by reducing the amounts of fat trim incorporated and by the inclusion of different apple products (fresh, rehydrated, and sauce). Panelists could discriminate between ground pork containing 15% or 30% fat (without apples) and between ground pork with 0% or 15% apple (25% fat) but not between formulations with 15% or 25% fat and 10% apple (p<0.05). Incorporation of apple products (15% of total formulation weight) into reduced-fat pork sausage containing 15% fat yielded formulations with comparable flavor and preference scores to sausage with 30% fat, depending on the apple product. Total fat of cooked pork sausage can be reduced by approximately 35% by incorporation of apple products (15%) into reduced fat pork sausage. Inclusion of fresh or rehydrated apples did not significantly influence psychrotrophic bacteria populations or the color of pork sausage stored at 1–2C up to eight days.     

Lipid composition of Australian pork cuts 2005/2006

A study of the cholesterol content and fatty acid composition of fresh retail Australian pork was undertaken to determine whether new breeding, feeding and processing methods had resulted in any compositional changes in fresh pork in the market place since surveys undertaken in previous decades. Samples of 13 popular pork cuts were purchased from randomly selected supermarkets and butchers’ stores in urban areas across the socioeconomic scale in three States of Australia, and analysed, separable fat and separable lean, in late 2005 and early 2006. Variability was low across States for saturated and monounsaturated fatty acids, but more pronounced for polyunsaturated acids. The separable lean portions of all pork cuts contained levels of n-3 fatty acids and conjugated linoleic acid (C18:1c9t11) in measurable but not nutritionally claimable amounts, whilst total trans fatty acid levels were very low. There appeared to be some differences in fatty acid composition across States that may have resulted from feeding method. Cholesterol contents were similar to levels in the 80s and 90s for separable lean pork tissue, but presently are lower for separable fat tissue than for separable lean.     

SENSORY AND NUTRITIVE QUALITIES OF PORK STRIPS PREPARED BY THREE HOUSEHOLD COOKING TECHNIQUES1

The sensory and nutritive qualities of pork strips cooked by household broiling, microwaving, and stir-frying methods were determined. Fresh pork hams from two sources were cut into 0.5 × 2.5 × 4 cm strips having no separable fat. Pork strips were cooked by each method, three replications, to 66C internal temperature. Sensory qualities were evaluated by a 14-member trained panel consisting of lifelong Nebraska Caucasian women and men. Nutrients which Americans frequently consume in low quantities were measured. Pork strips that were cooked by stir-frying were significantly browner, more tender, and more juicy than those cooked by broiling or microwaving. Strips cooked by stir-frying were significantly more characteristic in flavor than those cooked by broiling but not microwaving. Significantly more vitamin B₆, thiamin, iron, magnesium, and zinc were retained in strips cooked by stir-frying than by the other two methods. Sensory attributes of pork strips cooked by stir-frying were generally more desirable and nutrient retention values higher than those cooked by microwaving or broiling.     

Subcellular Distribution of Cholesterol within Muscle and Adipose Tissues of Beef Loin Steaks

Subcellular distribution of cholesterol (membrane versus storage components) within muscle and adipose tissue of raw and cooked beef longissimus steaks from three quality grades and three subcutaneous fat trim levels was determined. In muscle tissue, 60–80% of total cholesterol was located in the membrane component while the storage component contained 20–40%. In adipose tissue, the membrane fraction contained 8–12% of total cholesterol while the storage fraction contained 88–92%. Cooking caused a significant change in cholesterol distribution between membrane and storage sites of adipose tissue. Quality grade affected (P < 0.05) subcellular distribution of cholesterol within muscle tissue, while subcutaneous fat trim level affected (P < 0.05) cholesterol distribution within adipose tissue.     

EFFECTS OF END-POINT TEMPERATURE AND FAT LEVEL ON THE RESIDUAL CHOLESTEROL IN GROUND BEEF PATTIES1

Patties of lean ground beef with 2% fat (L2PF) and 6% fat (L6PF) were used to study the fat and cholesterol composition of raw and cooked ground beef and to determine how the end-point cooking temperature affects the amount of fat and cholesterol in a lean ground beef patty as it would be eaten by the consumer. The two patty types were obtained from the longissimus muscle of steers with marbling scores associated with “Standard” to “Select” and “Select” to “Choice” U.S. carcass grades of beef, respectively. All steers were fed a diet of roughage and concentrates to ensure fat deposition over the 12th and 13th ribs; longissimus muscles between the 7th and 10th ribs were removed, trimmed of all external fat, ground and formed into three 130-g patties. One patty was fried to an internal temperature of 60C, another to 71C and the third was uncooked. After frying, the patties were measured for drip loss, moisture and total fat. The fat extract was used for cholesterol analysis. The cooked L2PF sample had significantly less fat than the cooked L6PF samples, but there was no difference between the L2PF and L6PF in cholesterol. End-point temperature had no effect on the fat and cholesterol contents for either L2PF or L6PF samples, but the higher end-point temperature resulted in a significant loss of moisture.     

Cholesterol Content and Sensory Analysis of Ground Pork as Influenced by Fat Level and Heating

Eight treatment combinations for the formulation and heating of fresh ground pork were investigated: four raw fat levels (4, 9, 18, 23%) and two internal end point temperatures (71°C and 77°C). In the raw state, ground pork containing 4 or 9% fat contained less cholesterol, more moisture and was judged to be more red than samples containing 18 or 23% fat. Tenderness, juiciness and amount of mouthcoating increased as fat level in the cooked patties increased. Internal end point temperature (71°C or 77°C) did not affect sensory scores of cooked pork patties. Cooked patty cholesterol content (wet weight) did not differ among the four fat levels. High-fat ground pork retained less cholesterol than low-fat ground pork.     

The storage stability and textural, physico-chemical and sensory quality of low-fat ground pork patties with Carrageenan as fat replacer

Low‐fat ground pork patties (<10% total fat) made with carrageenan added at either 0.25, 0.50 or 0.75% final concentration were processed and the compositional and sensory characteristics compared with control patties which contained 20% fat. The moisture content of raw and cooked low‐fat patties was significantly (P < 0.05) higher than control patties because of greater amounts of water added during formulation. Cooking yield, fat and moisture retention also improved significantly (P < 0.05) in low‐fat patties that had carrageenan incorporated when compared to a control product. The dimensions of the low‐fat patties were maintained better than those of the control product during cooking. The sensory attributes of low‐fat patties with 0.5% carrageenan were similar to those of the high‐fat control. The lipid profile revealed as much as a 47.7 or 44.1% decrease in total lipids and cholesterol content respectively, compared with the controls. The calorie content was reduced by 31.1% in low‐fat cooked patties compared with the controls. The texture profile of low‐fat patties that had been made with 0.5% carrageenan were similar to control patties with only a slight increase in hardness and gumminess in the low‐fat product. The low‐fat ground pork patties made in the present study remained stable without any appreciable loss of physico‐chemical, microbiological and organoleptic quality during refrigerated storage (4 ± 1 °C) for 21 and 35 days in aerobic and vacuum packaging respectively.     

Nutrient composition of Australian retail pork cuts 2005/2006

A study of the nutrient composition of Australian pork was undertaken to determine whether new breeding, feeding and processing methods had resulted in any changes in pork samples in the market place since surveys undertaken in previous decades. Samples of 13 popular pork cuts were purchased from randomly selected supermarkets and butchers’ stores in urban areas across the socioeconomic scale in three States of Australia, and analysed, raw and cooked, separable fat and separable lean, for nutrient composition (proximate components, minerals, vitamins) in late 2005 and early 2006. Results showed that present-day pork separable lean tissue continues to be low in fat, in line with stated objectives of practices implemented by the industry in Australia. Pork remains a good source of protein and of thiamin and other water-soluble vitamins, the latter being detected at nutritionally significant levels in fat tissue as well as lean; folate was detected in most samples, lean and fat portions. Iron content appeared to be slightly lower than in previous decades.     

Cutability comparisons of Charolais crossbred bulls and steers

Seventy-two sides (eighteen sides from each sex-breed group) from carcasses of half-blood or three-quarters-to-seven-eighths-blood Charolais bulls or steers of known history and age, handled alike from weaning to slaughter, were used. All cattle were fed in a commercial feedlot (average days-on-feed was 186) and slaughtered in a commercial packing plant. Comparisons were made for percentages of (1) untrimmed wholesale cuts, (2) partially boneless subprimals (trimmed of fat in excess of 1·9 cm), (3) partially boneless retail-ready cuts (trimmed of fat in excess of 0·95 cm) and (4) boneless retail-ready cuts (trimmed of fat in excess of 0·95 cm). Bulls had higher percentages than steers of chuck and round at all stages of trim. Steers had higher percentages of untrimmed, wholesale loin and partially boneless shortloin (1·9 cm fat) than bulls but steer percentages of shortloin cuts trimmed to 0·95 cm of fat did not differ from those of bulls. Bulls averaged 48·05%, while steers averaged 45·45%, major boneless, closely trimmed retail-ready cuts. After the lean trim was adjusted to 25% chemical fat, bulls had 27·70% lean trim and 5·65% fat trim while steers had 24·30% lean trim and 12·15% fat trim. No difference in the percentage of retail-ready cuts was attributable to breed; however, the three-quarters-to-seven-eighths-blood Charolais group had a lower percentage of standardized fat trim and a slightly higher percentage of bone than the half-blood group.     

Functionality of cow beef in coarse and fine ground model systems

Patties and sausage batters were made from trimmed brisket, chuck, striploin, hindshank, silverside, thick flank and rib trim from grass-fed Friesian cows. Functionality of each meat cut was determined from cook yield and true stress and strain of cooked sausage batters and cook yield, dimensional changes and peak force of cooked patties. Colour of raw and cooked slices from the meat cuts and cooked batters was evaluated using a colorimeter and a consumer panel. Composition of raw meat from all cuts was similar; chuck and rib trim had higher pH values and were more red than meat from other cuts. Cooked batters from striploin, chuck and hindshank had higher stress and strain values than gels from other cuts. Patties made from thick flank and striploin were the softest and had the highest cook yield. Batters and patties made from meat with higher salt soluble protein content retained more water and fat on cooking, were more cohesive and had higher bind strengths. Manufacturers can use functionality characteristics to select meat for specific products.     

Fatty acid and proximate composition of raw and cooked retail cuts of beef trimmed to different external fat levels

Beef steaks and roasts from US Choice, US Select and US Standard quality grades were used to determine the effect of 0·64 cm external fat trim and zero (no external fat) trim on the proximate and fatty acid composition of cooked cuts of beef. Total fat percentage of the cooked lean was affected by external fat trim, quality grade, cooking and degree of doneness. Fat retention percentages were higher in tenderloin and clod samples when cooked with external fat attached than when cooked with no external fat. No consistent effect of fat trim level or degree of doneness on the percentage of specific fatty acids was observed.     

Composition of Cooked Pork Chops: Effect of Removing Subcutaneous Fat Before Cooking

Conventionally trimmed (0.6 cm) and completely trimmed (0 cm) prok chops were used to evaluate the effect of removing subcutaneous fat on lipid retention during broiling of pork. Composition of the lean portion of cooked chops was not affected by removal of external fat before cooking. Conventional chops contained 4.4% either extractable lipid and completely trimed chops contained 4.3%. Lipid retention was also the same at 94–99%. Recovery of moisture, protein, and lipid was 98–99%, using ether extraction or chloroform:methanol extraction. Therefore, the concept of lipid migration during cooking was not a tenable explanation for reports of lipid retention exceeding 100% during broiling of pork chops typical of those available to consumers.     

ADDITION OF CORN GLUTEN MEAL AND ZEIN TO GROUND PORK OF VARIOUS FAT PERCENTAGES1

Corn gluten meal and zein at levels of 0, 2.5 and 5% were added to ground pork of three fat percentages. Raw patties were analyzed for fat, moisture, protein contents and color. Selected patties, broiled to 77°C, were evaluated for proximate composition, total cooking loss, color and Instron compression. Five percent zein added to ground pork reduced cooking loss 4.2% when compared with ground pork without zein. Addition of corn gluten meal to pork did not influence yield. Instron compression values increased with the addition of zein and corn gluten meal. Increased fat altered the hue (increased hue angle due to increased b) of the interior of the cooked pork patties. Zein addition also increased the lightness of cooked pork patties. The addition of zein to ground pork patties decreased sensory tenderness and pork flavor intensity and increased off-flavor intensity.     

SELENIUM AND TOCOPHEROL CONTENT OF COOKED PORK ROASTS1

The content and the retention of the antioxidant nutrients, selenium and tocopherol (vitamin E), in boneless Chef's Prime^TM pork loin roasts cooked by different methods to 71 and 82C internal temperatures were determined. Roasts were cooked at 163C by roasting, braising, and in an oven cooking bag. Yield, moisture, and crude fat measurements were similar for all treatments. The only form of vitamin E in the sample was α-tocopherol. Selenium and vitamin E content as well as true retention values were similar in pork cooked to the two internal temperatures by the three household methods with one exception; the selenium content was significantly higher in pork cooked in the bag and roasted than in those prepared by braising. Overall, the selenium and vitamin E content of the cooked pork was 101.8 ± 0.5 μg/100g (X?± SEM) and 0.144 ± 0.006 mg α-TE/100g, respectively. Over half of the vitamin E but little to none of the selenium in the pork was lost during these household cooking procedures.