Proteolysis and sensory properties of dry-cured bacon as affected by the partial substitution of sodium chloride with potassium chloride

Quadriceps femoris muscle samples (48) from 24 pigs were processed into dry-cured bacon. This study investigated the influence of partial substitution of sodium chloride (NaCl) with potassium chloride (KCl) on proteolysis and sensory properties of dry-cured bacon. Three salt treatments were considered, namely, I (100% NaCl), II (60% NaCl, 40% KCl), and III (30% NaCl, 70% KCl). No significant differences were observed among treatments in the proteolysis, which was reflected by SDS–PAGE, proteolysis index, amino acid nitrogen, and peptide nitrogen contents. Furthermore, there were no significant differences in the moisture content between control and treatment II, whereas the moisture content in treatment III was significantly higher (p < 0.05) in comparison with control (treatment I). The sensory analysis indicated that it was possible to reduce NaCl by 40% without adverse effects on sensory properties, but 70% replacement of NaCl with KCl resulted in bacon with less hardness and saltiness and higher (p < 0.05) juiciness and bitterness.     

Feeding differently processed soya bean Part 1. Effect on performance,protein utilization,relative organ weights,carcass traits and economics of producing broiler-chickens

The comparative utilization of differently processed (roasted, cooked and oil cake) soya bean base diets and groundnut cake diet were evaluated in a feeding trial using 100 day-old Anak broiler-chicks. The response criteria included performance, protein utilization, relative organ weights, carcass traits and economy of production. At the end of the feeding trial, the average weight gains of chicks fed processed soya bean diets were significantly (P < 0.05) higher than those fed groundnut cake and raw soya bean diets. Both feed consumption and efficiency were significantly (P < 0.05) enhanced by processing. For example, feed consumption was highest in the chicks fed soya bean oil cake and least in those fed raw bean. Feed efficiency was best in chicks fed roasted soya bean. The relative weights [g/100g body wt.] of the liver, kidneys, lungs, heart, gizzard and bursa were not significantly affected by the differently processed soya bean while the raw bean (unprocessed) significantly (P < 0.01) increased pancreas weight. The dressed weight [%], eviscerated weight [%] and the relative weight of the thigh, drumsticks, chest, back and head were not significantly influenced by the dietary treatments. However, the relative weights of the shank and belly fat were significantly (P < 0.05) affected. Cost-benefit analysis showed that the processed soya bean gave higher profit than groundnut cake diet. Among the soya bean diets, profit was in the order: roasted > cooked > oil cake > raw bean.     

Effects of dietary antioxidants on the quality, fatty acid profile, and lipid oxidation of longissimus muscle in Kacang goat with aging time

Thirty-two male goats were randomly assigned to four dietary treatments namely, basal diet 70% concentrate and 30% oil palm fronds (control, CN), CN + 400 mg/kg vitamin E (VE), 0.5% turmeric (TU) or 0.5% Anderographis paniculata (AP). After 100 days of feeding, the goats were slaughtered and longissimus dorsi (LD) muscle was sampled. The muscle was vacuum-packaged and conditioned for 0, 7 and 14 days in a chiller (4 °C). The drip loss of the LD muscle increased (P < 0.05) with aging time. Meat tenderness was improved (p < 0.05) at 14 days aging. All antioxidant supplements improved (P < 0.05) colour of the meat. The TBARS value increased (P < 0.05) at 7 days of aging while the fatty acid composition was not affected by the dietary supplements. It is concluded that TU and AP are potential dietary antioxidant supplements, for the purpose of improving the quality of chevon.     

Effects of Salt, BHA/BHT, and Differing Phosphate Types on Quality and Sensory Characteristics of Beef Longissimus Muscles

ABSTRACT:  USDA Select striploins ( n  = 20) were cut into thirds (anterior, medial, and posterior) and randomly assigned to 1 of 6 treatments. Treatments included: (1) control (C); (2) 0.006% BHA (butylated hydroxyl anisole)/BHT (butylated hydroxytoluene) (70%/30%) (BB); (3) 0.4% trisodiumphosphate (CT); (4) 0.4% sodiumtripolyphosphate with 0.5% salt (BH); (5) sodiumtripolyphosphate, 0.5% salt, and 0.006% BHA/BHT (70%/30%) (SB); (6) 0.2% sodiumtripolyphosphate, 0.2% trisodiumphosphate, and 0.5% salt (STB). Muscle sections were injected to 110% (10% pump) of their weight with their respective treatments. Inclusion of BHA/BHT allowed for lower mean oxidation values. Regardless of phosphate type, muscles treated with both phosphate and salt had lower retail purge ( P < 0.05). Sensory panelists rated ( P < 0.05) STB, SB, and BH to be juicier than all other treatments. These data suggest that inclusion of both salt and phosphate can enhance palatability, lower cook loss, and retail purge.     

EFFECTIVENESS OF CHLORINE AND NISIN‐EDTA TREATMENTS OF WHOLE MELONS AND FRESH‐CUT PIECES FOR REDUCING NATIVE MICROFLORA AND EXTENDING SHELF‐LIFE1

Efficacy of nisin‐EDTA treatments as a sanitizing treatment for reducing native microflora of whole melons and extending shelf‐life of fresh‐cut pieces was compared to chlorine treatments. Whole cantaloupe and honeydew melons were washed with water, nisin (10 μg/mL)‐EDTA (0.02 M), or 200 ppm chlorine for 5 min at ～ 20C before fresh‐cut preparation and storage at 5C for 15 days with periodic microbiological sampling. In addition, some fresh‐cut pieces were washed with 10 μg/mL nisin‐EDTA or 50 ppm chlorine for 1 min before storage. Changes in appearance, odor, overall acceptability and the shelf‐life of the minimally processed fresh‐cut melons were investigated. Preliminary studies indicated that water washes, EDTA (0.002 to 0.2 M) or nisin (5 to 10 μg/mL) were not effective in reducing the microflora of whole melon when used individually. Nisin‐EDTA and chlorine treatments were significantly (P < 0.05) more effective in reducing native microflora than water washes. Nisin‐EDTA treatments were significantly (P < 0.05) more effective than chlorine in reducing populations of yeast and mold and Pseudomonas spp. on whole melon surfaces but were not as effective as chlorine treatments for reducing aerobic mesophilic bacteria, lactic acid bacteria and total gram‐negative bacteria. Microbial contaminants on fresh‐cut pieces washed with 50 ppm chlorine or nisin‐EDTA were further reduced. However, microbial populations increased throughout refrigerated storage irrespective of treatments. Odor, appearance, and overall acceptability ratings for cantaloupe and honeydew fresh‐cut pieces treated with nisin‐EDTA or chlorine were not significantly (P > 0.05) different from each other throughout the storage period (15 to 21 days). However, both treatments led to significantly (P < 0.05) improved ratings compared to the controls for the fresh‐cut pieces at 9 to 12 days of storage and thereafter. The results of this study suggest that treatments with nisin‐EDTA before and after fresh‐cut processing would improve the quality and extend the shelf‐life of fresh‐cut melon.     

Feeding differently processed soya bean Part 3. Effect on serum constituents and bone mineralization in the chicken

The effect of feeding differently processed soya bean on serum constituents and bone mineralization in the chicken was investigated in growing chickens. The response parameters were total serum protein (TSP), albumin, globulin, albumin: globulin ratio and urea. Others were phosphorus, calcium and calcium: phosphorus ratio in the tibia and femur. The results indicated that TSP was significantly increased (P < 0.05) in the heat processed soya bean diets but decreased in the chicks fed raw soya bean diet. Albumin and globulin were not significantly affected. However, albumin: globulin ratio was significantly (P < 0.05) influenced. Serum urea was generally higher (P < 0.05) in the chicks fed processed soya bean diets. Significant (P < 0.01) decrease was observed in the total ash [%] of the bones in the chickens fed raw soya bean diet. The phosphorus [%] and Ca:P ratio in both tibia and femur were not significantly affected by dietary treatments.     

The application of high-pressure treatment in the reduction of salt levels in reduced-phosphate breakfast sausages

This study investigated the effects of high pressure (HP) treatment of pork meat before manufacturing sausages with reduced salt levels and compared them to sausages manufactured with untreated meat (control sausages). A 2 × 5 factorial design was set up incorporating two pressure levels (0 or 150 MPa) and five salt levels (0.5, 1.0, 1.5, 2.0 and 2.5%). Most quality attributes were affected when salt levels were reduced below 1.5%. Fat loss (FL) was (P < 0.05) affected by salt level; samples with < 1.5% salt had the highest FL. HP treatment increased emulsion stability and reduced cook loss (CL) compared to control sausages. Increased CL was observed when salt was reduced below 2.0%. Salt reduction below 1.5% adversely affected colour, sensory and texture attributes. Independent of salt, HP treatment affected adversely juiciness and cohesiveness while adhesiveness was improved. Overall, there is potential to manufacture sausages maintaining organoleptic and functional properties traditionally associated with sausages using HP treated meat.     

THE EFFECT OF CARCASS ELECTRICAL STIMULATION ON MEAT OBTAINED FROM BOS INDICUS AND BOS TAURUS CATTLE1

Sides of 30 carcasses obtained from steers of Hereford and Angus (HA), Braham (Br) or Sahiwal (Sh) crossbreds were electrically stimulated (ES) by high voltage or remained as controls (CN). Longissimus muscle at the 12th rib of carcasses from the Br and Sh crossbreds was darker (P < 0.05) in color and possessed greater (P < 0.05) degrees of dark coarse band formation than muscle from the HA crossbreds. Broiled steaks from carcasses of Br and Sh crossbreds were less tender than steaks from HA. Electrical stimulation markedly improved (P < 0.05) dark coarse band formation, color and tenderness of steaks within the Bos indicus breed groups. Improved tenderness was associated with better (P < 0.05) sensory panel scores for ease of fragmentation of the myofibrillar portion and less (P < 0.05) connective tissue.     

STABILITY OF RED KIDNEY BEAN LECTIN1

ABSTRACT Lectins are toxic heat-stable glycoproteins, termed phytohemagglutinins, that depress the nutritional quality of Phaseolus vulgaris. Purified phytohemagglutinin (PHA-P) was separated from dark red kidney beans (Montcalm cultivar) by affinity chromatography and subjected to various treatments including: thermal (70–100C; chemical (2 M NaCl, 5 M urea, 5% mercaptoethanol, pH 12 and pH 3) and enzymatic (peptidases, proteases and carbohydrases). At 70C, the PHA-P activity decreased with a linear response. Exposure to pH 12 or 5 M urea were the most effective chemical treatments for reducing hemagglutinating activity. Treatment with proteases resulted in 88–98 % reductions in PHA-P activity. Man-nosidase treatment resulted in a slight but significant (P < 0.01) reduction in activity; however, amylases and neuraminidase had no effect on activity. Terminal sialic acid residues may not be an important determinant of PHA-P activity.     

HIGH TEMPERATURE DRYING CHARACTERISTICS AND MOISTURE ADSORPTION ISOTHERMS OF BLACK PLUM (VITEX DONIANA) SYRUP AND SYRUP-STARCH

Modified sweeteners were formulated from mixtures of Black plum syrup and phosphorylated corn starch concentrations of 20, 30, and 40% (w/w). Each mixture was coated on an aluminium plate at 1 mm thickness, dehydrated at 60°, 70°, 80° and 90°C, and evaluated for drying and moisture sorption characteristics. Results showed that the mixtures exhibited falling rate drying characteristics. The rate of dehydration increased in the order 20% > 30% > 40% starch at constant temperature. The incremental choice of 10% starch and drying temperature except at 70° and 80°C had significant effect (p < 0.05) on drying rate. The moisture isotherm curves of the pre-dried mixtures were sigmoid in shape. Their monolayer values or upper critical moisture contents necessary for shelf-stability were significantly different from each other for the samples pre-dried at 60°C. The effect of drying temperatures on equilibrium moisture content was only significant at 90°C (p < 0.05).     

低钠盐对皮蛋的钠钾含量、硬度及蛋白质二级结构的影响

以新鲜鸭蛋为原料,采用清料法腌制皮蛋。探讨低钠盐替代食盐对皮蛋的钠钾含量、凝胶的硬度、蛋清蛋白质二级结构、感官品质等的影响,旨在为降低皮蛋中的钠含量提供新的思路,为加工低钠皮蛋提供新的方向。结果表明,100%低钠盐组比食盐组蛋清钠含量降低了21%,蛋黄钠含量降低了30%。不同比例的低钠盐替代组与食盐组对比,皮蛋凝胶的硬度、蛋清蛋白质二级结构的含量均无显著性差异(p>0.05)。70%低钠盐替代食盐制得的皮蛋,感官品质良好。      

Carcass maturity and dicationic salts affect preblended, low-fat, low-sodium restructured beef

Preblending A- and C-maturity muscles with MgCl(2) and/or CaCl(2) was investigated in low-fat, low-sodium restructured beef. Products were formulated to contain: 1) 80% chunks, preblended 12h with 0.05% MgCl(2), 0.05% CaCl(2), or a combination of each (0.1%) and 0.4% sodium tripolyphosphate (STPP) and 2) 20% mince preblended 12h with 0.05% of each dicationic salt or the combination of dicationic salts (0.1%), 0.4% STPP, and 1.0% NaCl. This formulation achieved a raw product NaCl content of 0.2%. Additionally, a control was formulated with chunks and mince that contained no dicationic salt. CaCl(2) decreased raw and cooked pH and cook yield, and increased cohesiveness; whereas, MgCl(2) increased cook yield and myosin solubility. Total protein solubility was not affected by muscle maturity or dicationic treatment. Myosin solubility of the combination treatment was greater for C-maturity muscle (57 months) compared to A-maturity muscle (20 months) formulations. Control, C-maturity muscle treatments contained more insoluble and total collagen (p < 0.05), and these treatments were more cohesive (p < 0.05) than control, A-maturity treatments. The combination of CaCl(2) and MgCl(2) increased hardness of A-maturity products, but it decreased hardness of C-maturity products. In addition to increasing hardness of A-maturity products, the combination treatment lowered (p < 0.05) cook yield for these products.     

EFFECT OF RAPID COOLING OF SHELL EGGS ON MICROCRACK DEVELOPMENT, PENETRATION OF SALMONELLA ENTERITIDIS, AND EGGSHELL STRENGTH

Eggs were subjected to cryogenic cooling treatments using liquid CO₂ or liquid N_2. In order to minimize the thermal stress in eggshells due to rapid cooling, a two-stage air-cooling method was also evaluated in this study. Eggs were cooled from an initial temperature of 25C to approximately 7C. It was found that cooling produced microcracks on eggshells. However, rapid cooling did not increase the penetration of Salmonella enterica serovar Enteritidis (Salmonella enteritidis) into egg contents. When egg contents alone were sampled for Salmonella enteritidis, extending the immersion time from 24 to 48 h significantly (P < 0.01) increased the penetration of Salmonella enteritidis from 5.0 to 25.0%. When egg contents together with eggshells were sampled, Salmonella enteritidis was detected in 100% of the egg samples at the above two time intervals. There were no significant differences (P > 0.05) in the eggshell strength between control (no cooling) and cooling treatments, indicating that cooling did not weaken eggshell strength.     

Nutritional value of an extruded spent hen–soybean meal blend for pigs and ruminants

Two studies were conducted to determine the feeding value of an extruded spent hen meal–soybean meal (SHSB) blend (50:50 spent hen/soybean meal) for pigs and ruminants. In the first trial, 60 crossbred pigs were assigned to one of five dietary treatments in which 0, 25, 50, 75 or 100% of soybean meal was replaced by the SHSB blend as a protein source. Total tract nutrient digestibility coefficients (obtained using the indicator method) were determined using six barrows per treatment. Results showed that digestibility coefficients for dry matter, crude protein (CP) and gross energy were not affected (P > 0.05) by the inclusion of the SHSB blend in the diet and averaged 75.3, 74.3 and 74.0% respectively. Average daily gain during the growing period (22–54 kg) increased (P < 0.05) as the level of the SHSB blend increased to 50% of the supplementary protein. However, higher replacement levels reduced the average daily gain of growing pigs (quadratic effect P = 0.037). Inclusion of the SHSB blend had no effect on average daily gain during the finishing period (54–76 kg). Feed intake decreased linearly (P = 0.042) as the level of the SHSB blend in the diet increased. Consequently, feed conversion improved linearly (P = 0.001) in response to increased levels of the SHSB blend. Two ruminally fistulated cows were used in the second trial to determine the ruminal degradability of the SHSB blend relative to meat meal, canola meal and brewers' grains. Effective ruminal CP degradability of the SHSB blend was similar to brewers' grains, lower (P < 0.05) than canola meal and higher (P < 0.05) than meat meal. The estimated ruminal undegraded protein value for the SHSB blend, meat meal, canola meal and brewers' grains was 547, 593, 417 and 546 g kg⁻¹ of CP, respectively. It was concluded that the SHSB blend could replace 50% of soybean meal during the growing period and 100% during the finishing period with no adverse effects on pig performance. The SHSB blend could serve as a source of both ruminal degraded and undegraded protein for ruminants. © 2000 Society of Chemical Industry     

PROCESSING CHARACTERISTICS AND YIELD OF PORK FRANKFURTERS MANUFACTURED FROM GILTS ADMINISTERED EXOGENOUS PORCINE SOMATOTROPIN

Eighteen gilts (75 kg) were injected daily with 0, 2.5, or 5 mg of porcine somatotropin (pST) for either 30 or 31 days prior to slaughter to examine the effects of dose of pST administration to swine on processing characteristics of frankfurters manufactured from pork. Frankfurters were manufactured from New York shoulders (NAMP #404) and formulated with fat from the same carcass to a final product target of 22% fat and 10% added water. Frankfurters from pST- treated gilts had lower smokehouse yields (0.9% decrease; P <.005) and greater shear force peak height (35.4% increase; P < 0.05) compared with the controls. The increased shear force required for skin failure of frankfurters manufactured from pork from pST-treated pigs was not readily explained by other differences due to treatment (e.g., cooking stability, batter proximate composition or salt soluble protein content; all P > 0.05)     

Structural changes of meat protein of chicken sausages with various levels of salt and phosphate and their effects on in vitro digestion

The objectives of this study were to evaluate protein oxidation and in vitro digestibility of chicken sausages with various salt/phosphate combinations. Hydrophobicity increased when protein was cooked and denatured (P < 0.05). Protein oxidation was increased based on levels of SH, S-S and carbonyl groups during the cooking process (P < 0.05). Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) revealed that the intensity of myosin heavy chain band was decreased while biopolymer band was denser when sausages were cooked. Sausages with 1.8% salt and 0.3% phosphate (S1P1) showed the lowest digestibility and maintained a flat and compact structure, unlike other treatments during the gastrointestinal digestive stage. SDS-PAGE of digested chicken sausages showed that protein bands were degraded into small bands followed by gradual disappearance. In conclusion, cooking process can lead to protein denaturation and oxidation, regardless of levels of salt and phosphate added. In addition, adding salt and phosphate can significantly affect the digestibility of meat products.     

DISTRIBUTION PACKAGING METHOD AND STORAGE TIME EFFECTS ON THE MICROBIOLOGICAL CHARACTERISTICS AND INCIDENCE OF THE PATHOGENS LISTERIA MONOCYTOGENES AND SALMONELLA IN PORK1

Microbiological and yield characteristics were determined on bone-in pork loins and Boston butts (n = 65 each) that were selected from a commercial facility and subjected to one of three packaging treatments: (1) paper wrapped, (2) modified atmosphere packaging (66% O, 2.26% CO₂ and 8% N₂), and (3) vacuum packaging. Cuts were stored up to 21 days at 0 ± 2C for yield characteristics and an added 28 and 35 days for microbiological characteristics. Treatment and storage effects on the incidence of the pathogens Listeria monocytogenes, Salmonella and numbers of aerobic bacteria, lactic acid bacteria and coliforms were determined. The amount of purge was variable (100 to 500 g) among packaging treatments. The vacuum packaged and modified atmosphere packed pork loins and butts had lower aerobic plate counts (P < .05) compared with the paper wrapped loins and butts. The numbers of Listeria species decreased at a greater rate for the vacuum packaged and modified atmospheric packaged pork loins compared with the paper wrapped loins. No Salmonella were found on meat from any packaging treatment or storage time. The microbial quality of pork loins and butts can be improved by using vacuum packaging compared with paper wrapping or modified atmosphere packaging.     

RAW MATERIAL pH, PUMP LEVEL AND PUMP COMPOSITION ON QUALITY CHARACTERISTICS OF PORK

ABTRACT
Boneless, paired pork loins (n=120) were selected based on pH at 14 h postmortem. Ultimate pH, drip loss, instrumental color (L*, a*, and b* values), and proximate analysis were determined prior to pumping. Paired loins were cut into four sections and pumped to 100%, 106%, 112% or 118% of original weight to result in a product containing 0.4% sodium tripolyphosphate (STP) for Experiment 1 (Exp. 1) and 0.4% STP plus 0.4% salt for Experiment 2 (Exp. 2). In Exp. I, additional pump level increased (P<0.05) vacuum package purge. Higher raw materials pH reduced purge. A pump level x pH interaction (P<0.05) occurred for cook loss at 70C. In Exp. 2, increased raw materials pH reduced (P<0.05) purge loss and resulted in juicier, more tender pork. Pumped pork had higher (P<0.05) tenderness, juiciness, and saltiness scores than controls.     

Effect of sodium chloride replacement and apple pulp inclusion on the physico-chemical, textural and sensory properties of low fat chicken nuggets

The effect of 40 percent sodium chloride replacement with salt substitute blend (potassium chloride, citric acid, tartaric acid and sucrose) and incorporation of apple pulp, at the levels of 8 (Treatment I), 10 (Treatment II) and 12 (Treatment III) g/100 g of formulation, on the various quality characteristics of low fat chicken nuggets was investigated. Emulsion and product pH values were significantly higher (P < 0.01) for the control when compared to treatments. Salt replacement and apple pulp addition resulted in significantly lower (P < 0.05) emulsion stability and cooking yield. Among low salt and low fat nuggets, the product with 12 g/100 g apple pulp had the highest moisture percent. Protein and ash contents were significantly lower (P < 0.01) in treatment products, whereas moisture protein ratio was higher. Incorporation of apple pulp significantly increased (P < 0.01) dietary fibre content, redness, yellowness and chroma index of the product. Textural properties of the products significantly decreased (P < 0.01) with substitution of common salt and addition of apple pulp. Sensory evaluation showed significant reduction (P < 0.01) in texture and overall acceptability scores of treatment products; however, scores were in the range of very good.