Reduction of Drying Time for Pepperoni by Vacuum-drying

Commercial pepperoni was dried under vacuum (100 kPa) at three temperatures (177°, 19°, and 22°C) and matching controls were dried under commercial conditions. Vacuum-dried pepperoni achieved a moisture: protein (M:P) ratio of 1.6:1 after 9 to 12 days drying, compared to 18 days for the control. Overall drying time was reduced ～30%. Among temperature treatments, 17°C treatment had more weight loss and darker color (P < 0.05) than others. Weight loss and Kramer shear force were higher (P < 0.05) for vacuum-dried pepperoni, whereas Hunter a and b values tended to be higher for the control throughout the drying period.     

EFFECT OF SPLEEN IN RESTRUCTURED BEEF

Boneless beef chucks were converted to restructured beef steaks and formulated with 1% NaCl and 0.25% sodium tripolyphosphate (STP). Experimental treatments included (1) control-frozen, (2) control-5 days storage at 0°C, (3) 1% spleen pulp-frozen and (4) 1% spleen pulp-5 days storage at 0°C. Treatments 2 and 4 were evaluated only after storage for 5 days; whereas, treatments 1 and 3 were studied at 5 and 70 days. Spleen pulp enhanced (P<0.05) color development during frozen storage for a short period but offered no (P>0.05) contribution to color preservation during prolonged storage. Visual color and overall appearance were affected more by storage time and conditions than by the addition of spleen pulp. Spleen pulp had no effect (P>0.05) on product cohesiveness, texture, tenderness and flavor of frozen restructured beef steaks but improved the tenderness of unfrozen samples.     

Particle Size and Mixing Time Effects on Sensory and Physical Properties of Low-fat, High-moisture Pork Frankfurters

Changes in particle size affected measured characteristics more than changes in mixing time. Sensory results indicated that use of a 2.0 mm plate produced the coarsest (P<0.05) product. CIE b* values decreased (<0.05) as particle size was increased. Products produced with a 2.0 mm plate compared to a 1.4 mm plate had higher (P<0.05) hardness values and total energy to shear. Particle size did not affect (P>0.05) cooking loss, springiness, cohesiveness, or chewiness. Additional mixing tended to decrease sensory particle size and increase springiness and chewiness.     

EFFECT, DEVELOPMENT AND OPTIMIZATION OF MIXING TEMPERATURE, TIME AND PARTICLE REDUCTION IN THE MANUFACTURE OF RESTRUCTURED BEEF STEAK

Restructured beef steaks were processed from USDA Select chuck muscles without the use of additives, and three processing variables were utilized at three different levels: -2, 0, +2C for mixing temperature, 12, 18, 24 min for mixing time and 1, 2, 3 passes through a kidney plate for particle size reduction. A sensory panel composed of 149 untrained consumer panelists evaluated the 27 treatment combinations for five sensory attributes. Instrumental determinations were also made. Increasing mixing temperature and decreasing particle size significantly decreased sensory tenderness, flavor and overall acceptance and increased instrumental hardness and springiness of the restructured beef steaks. Increasing mixing time had a significant effect on sensory appearance and on instrumental cohesiveness and gumminess. The means for sensory scores were used for a response surface analysis (RSM) to optimize the three processing variables. Significant models were found for tenderness (P<0.05), overall acceptance (P<0.05) and flavor (P<0.15). Using a sensory score of 6.00 (like slightly) as an acceptable score, optima for the processing variables were determined. To obtain an acceptable product, the meat should be ground by two passes through the kidney plate then mixed at a maximum temperature of 0.67C for 12 min.     

Prooxidant effects of the combination of green tea extract and sodium nitrite for accelerating lipolysis and lipid oxidation in pepperoni during storage

Abstract: The individual and interactive effects of green tea (GT) extract and sodium nitrite (NT) on lipolysis and lipid oxidation were investigated in pepperoni during processing and storage (4 °C). Pepperoni was treated with GT at concentrations of 0.02%, 0.05%, 0.1%, 0.2%, 0.5%; and NT from 0.003% to 0.015% in increments of 0.003%; and a combination of 0.05% GT and 0.009% NT (GT/NT). The pH, color, residual nitrite, fatty acid (FA), and 2‐thiobarbituric acid reactive substances (TBARS) values were measured. The results showed inhibitory effects on TBARS value were concentration dependent. The largest effect was at 0.05% for GT and 0.009% for NT. Adding 0.05% GT significantly decreased (P < 0.05) the TBARS values but did not affect color values during storage. NT (0.009%) was more effective than GT (0.05%) for maintaining lower TBARS values (P < 0.05). Total fatty acids were not affected by 0.05% GT and 0.009% NT treatments. However, adding GT/NT showed a significant prooxidant effect (P < 0.05) in pepperoni, which accelerated lipolysis and lipid oxidation significantly (P < 0.05) during storage, with depletion of nitrite. This suggests that adding GT and an appropriate amount of NT into pepperoni could promote lipolysis and lipid oxidation during storage, as compared to NT alone. Practical Application: When using GT extract as an antioxidant in industrial production of pepperoni, the interaction effect with NT should be considered, as it may lead to a prooxidant effect during refrigerated storage.     

Effects of High‐Hydrostatic Pressure on Inactivation of Human Norovirus and Physical and Sensory Characteristics of Oysters

The purpose of the study was to determine the effect of high‐hydrostatic pressure (HHP) on inactivation of human norovirus (HuNoV) in oysters and to evaluate organoleptic characteristics of oysters treated at pressure levels required for HuNoV inactivation. Genogroup I.1 (GI.1) or Genogroup II.4 (GII.4) HuNoV was inoculated into oysters and treated at 300 to 600 MPa at 25 and 0 °C for 2 min. After HHP, viral particles were extracted by porcine gastric mucin‐conjugated magnetic beads (PGM‐MBs) and viral RNA was quantified by real‐time RT‐PCR. Lower initial temperature (0 °C) significantly enhanced HHP inactivation of HuNoV compared to ambient temperature (25 °C; P < 0.05). HHP at 350 and 500 MPa at 0 °C could achieve more than 4 log₁₀ reduction of GII.4 and GI.1 HuNoV in oysters, respectively. HHP treatments did not significantly change color or texture of oyster tissue. A 1‐ to 5‐scale hedonic sensory evaluation on appearance, aroma, color, and overall acceptability showed that pressure‐treated oysters received significantly higher quality scores than the untreated control (P < 0.05). Elevated pressure levels at 450 and 500 MPa did not significantly affect scores compared to 300 MPa at 0 °C, indicating increasing pressure level did not affect sensory acceptability of oysters. Oysters treated at 0 °C had slightly lower acceptability than the group treated at room temperature on day 1 (P < 0.05), but after 1 wk storage, no significant difference in sensory attributes and consumer desirability was observed (P > 0.05).     

Low-Fat, High-Moisture Frankfurters: Effects of Temperature and Water during Extended Mixing

Frankfurters containing 15% fat and 25% added water were produced using conventional practice or minced meat batters were mixed for 30 min (extended mixing, EM) at 2 or 16°C with all or 30% of the formulation water. EM had minimal effects on yield, purge, and texture. Products were darker and less yellow than non-EM frankfurters. The lower mixing temperature resulted in firmer (P < 0.05) frankfurters. However, mixing temperature did not affect other properties. Time of water addition affected most properties. Frankfurters from treatments mixed with 100% of formulation water were firmer, darker, redder, less yellow, and required more extension to fracture.     

Flavor and Oxidative Stability of Ground Beef Patties as Affected by Source and Storage

Chuck muscles and fat from silage plus grain- and forage-fed steers were stored 7 days at 4°C before patty manufacture or processed into patties and stored at 4°C or ?32°C. The thiobarbituric acid values were constant from 0 to 4 days for frozen patties but decreased (P<0.05) for refrigerated patties. Evaluated by an 11-member trained sensory panel, frozen patties had lower (P<0.05) rancid flavor intensity than refrigerated patties; rancid flavor increased from 0 to 2 or 4 days storage in refrigerated patties. Frozen patties from silage plus grain-fed steers had higher (P<0.05) beefy flavor intensity scores than those from forage beef. However, diet source had no effect (P>0.05) on refrigerated patties.     

Effects of calcium salts on beef longissimus quality

The objective of this research was to evaluate the effects of injection marination with calcium salts on beef longissimus quality traits. Strip loins were injected (11% by weight) with distilled water or a 0.1, 0.2, or 0.3 M solution of calcium ascorbate, calcium chloride, or calcium lactate. Non-injected loins served as controls. Visual and instrumental color evaluations indicated that calcium ascorbate accelerated myoglobin oxidation, and increasing molar concentration of any calcium salt caused faster (P<0.05) discoloration. Aerobic microbial plate counts were lower (P<0.05) for treatments containing calcium lactate than those with calcium chloride or calcium ascorbate. Calcium ascorbate inhibited lipid oxidation whereas calcium lactate and calcium chloride appeared to be pro-oxidants of lipid oxidation. No differences for Warner-Bratzler shear force or sensory panel tenderness were found among the calcium salts; however, 0.3 M treatments had lower shear values and were judged more tender than 0.1 M treatments. Calcium ascorbate and calcium chloride treatments resulted in less (P<0.05) beef flavor and more (P<0.05) off-flavors than calcium lactate treatments. In addition, 0.1 M treatments had higher (P<0.05) beef flavor scores while 0.3 M treatments had higher (P<0.05) off-flavor scores. Considering the effects on color life, microbial inhibition, shear force, and sensory traits, we recommend injecting beef longissimus with a 0.1 M solution of calcium lactate to enhance both uncooked and cooked quality.     

Cooking Temperature, Bird Type, and Muscle Origin Effects on Sensory Properties of Broiled Emu Steaks

Trained sensory panel scores and Warner-Bratzler shear values (WBS) of emu meat cooked to three end-point temperatures (60, 66, and 75°C), obtained from two bird types (breeder quality, BQ; and nonbreeder quality, NBQ), and from five carcass locations were determined and compared in three studies. NBQ birds had obvious conformational defects. Full rumps and inside drums broiled to 60°C were more tender and juicy than those broiled to 66 or 75°C (P<0.05). Cooking temperature did not affect meat-flavor intensity (p>0.05). BQ vs NBQ sources had no effect on tenderness or juiciness (p>0.05). Differences in tenderness, juiciness, meat-flavor intensity and WBS were found among the five meat cuts (P<0.05).     

Effect of Gradual Heating and Fat/Oil Type on Fat Stability,Texture, Color,and Microstructure of Meat Batters

The effects of endpoint cooking temperature (40, 50, 60, 70, 80, and 90 °C) on emulsion stability, texture, color, and microstructure of meat batters prepared with different fats/oils were studied. Canola oil treatments showed the highest cooking loss whereas hydrogenated palm oil provided the most stable meat batters. Rendered beef fat was less stable than regular beef fat. Increasing endpoint cooking temperatures resulted in a progressive reduction of water holding capacity in all treatments. As temperature was raised, meat batters showed higher hardness and cohesiveness values, but no appreciable changes in cohesiveness above 60 °C. Canola and hydrogenated palm oil treatments showed the highest hardness and chewiness values. Lightness (L^*) values of all meat batters increased significantly with increasing temperature from 40 to 60 or 70 °C; no major changes observed above 70 °C. Light microscopy revealed no substantial changes in the microstructure of all the stable meat batters cooked to between 50 and 70 °C. Heating to 90 °C changed the microstructure in all meat batters except the hydrogenated palm oil treatments, which still showed nonround fat particles and a less aggregated protein matrix.     

Physicochemical and sensory quality of wines from red sorrel/roselle (Hibiscus sabdariffa L.) calyces: effects of pretreatments of pectolase and temperature/time

The effects of pretreating red sorrel (Hibiscus sabdariffa L.) calyces on the physicochemical and sensory quality of wines were investigated. Sorrel calyces were processed at 60 °C for 3.5 h or 90 °C for 30 min at 0%, 0.5% and 1.0% w/w pectolase addition in fermentation of wines. Significant changes (P < 0.01) in all physicochemical parameters of sorrel wines were found during fermentation, but not (P > 0.05) because of temperature/time effects. Colour (P < 0.01) became redder with pectolase and on storage at 23 °C for 2 months. Significant differences (P < 0.01) were noted in sensory quality for taste and flavour, balance, duration and overall quality. Higher (P < 0.01) overall sensory quality scores were obtained for wines by pretreatment at 90 °C for 30 min (10.44–11.06/20) when compared with wines at 60 °C for 3.5 h (6.88–9.06/20). Colour of wines from 90 °C/30 min was most saturated and red than all wines and had pH 2.57 ± 0.01, 0.43 ± 0.07% citric acid, 10.53 ± 0.53 °Bx and 15.29 ± 0.71% alcohol.     

Effects of ultrasound-assisted frying on the physiochemical properties and microstructure of fried meatballs

The aim of this study was to investigate the effects of power ultrasound (0, 200, 400, 600 and 800 W, 20 kHz) on the quality of fried meatballs. The frying time and frying temperature were also considered as fixed factors. The meatballs were fried for 8, 12 and 16 min at 120, 140 and 160 °C. Results showed that the ultrasonic groups saved about 1 to 3 min than the control group to 80 °C. Hardness, springiness, cohesiveness and chewiness of fried meatballs were significantly different among different ultrasonic treatments (P < 0.05). As for colour, the ultrasonic treatments could significantly increase the L*values. Cooking yield was from 82.58% to 85.50% in ultrasonic treatments at 120 °C for 8 min. High moisture retention and cooking yield were shown in fried-assisted ultrasound treatments and were consistent with the microstructure of scanning electron microscopy (SEM). Our data show that ultrasound-assisted frying could improve the quality of meatballs.     

Storage Stability of Low-fat Ground Beef Made with Lower Value Cuts of Beef

Five combinations of low-fat ground beef treatments were prepared with lower value raw-materials: 90% lean cow trimmings, 50/50 Choice trimmings, 95% lean Choice trimmings, defatted clods and rounds, cow knuckles, and cow chucks. They were compared to a 20% fat control for quality attributes during 24 wk frozen (?20°C) storage. Control patties had greater (P<0.05) cooking loss, shear force, and connective tissue, and lower (P<0.05) juiciness scores than low-fat treatments. All low-fat pattie treatments were rated higher (P<0.05) in flavor intensity than control patties. Low-fat patties manufactured with a majority of lean cow trimmings had a greater color (pigment) and oxidative (lipid) stability.     

The Influence of Bleaching Agent and Temperature on Bleaching Efficacy and Volatile Components of Fluid Whey and Whey Retentate

Fluid whey or retentate are often bleached to remove residual annatto Cheddar cheese colorant, and this process causes off‐flavors in dried whey proteins. This study determined the impact of temperature and bleaching agent on bleaching efficacy and volatile components in fluid whey and fluid whey retentate. Freshly manufactured liquid whey (6.7% solids) or concentrated whey protein (retentate) (12% solids, 80% protein) were bleached using benzoyl peroxide (BP) at 100 mg/kg (w/w) or hydrogen peroxide (HP) at 250 mg/kg (w/w) at 5 °C for 16 h or 50 °CC for 1 h. Unbleached controls were subjected to a similar temperature profile. The experiment was replicated three times. Annatto destruction (bleaching efficacy) among treatments was compared, and volatile compounds were extracted and separated using solid phase microextraction gas chromatography mass spectrometry (SPME GC‐MS). Bleaching efficacy of BP was higher than HP (P < 0.05) for fluid whey at both 5 and 50 °C. HP bleaching efficacy was increased in retentate compared to liquid whey (P < 0.05). In whey retentate, there was no difference between bleaching with HP or BP at 50 or 5 °C (P > 0.05). Retentate bleached with HP at either temperature had higher relative abundances of pentanal, hexanal, heptanal, and octanal than BP bleached retentate (P < 0.05). Liquid wheys generally had lower concentrations of selected volatiles compared to retentates. These results suggest that the highest bleaching efficacy (within the parameters evaluated) in liquid whey is achieved using BP at 5 or 50 °C and at 50 °C with HP or BP in whey protein retentate.     

Effects of High Hydrostatic Pressure on the Physical,Microbial, and Chemical Attributes of Oysters (Crassostrea virginica)

The change in the quality attributes (physical, microbial, and chemical) of oysters (Crassostrea virginica) after high hydrostatic pressure (HHP) treatment at 300 MPa at room temperature (RT, 25 °C) 300, 450, and 500 MPa at 0 °C for 2 min and control oysters without treatment were evaluated over 3 wk. The texture and tissue yield percentages of oysters HHP treated at 300 MPa, RT increased significantly (P < 0.05) compared to control. Aerobic and psychrotrophic bacteria in control oysters reached the spoilage point of 7 log CFU/g after 15 d. Coliform counts (log MPN/g) were low during storage with total and fecal coliforms less than 3.5 and 1.0. High pressure treated oysters at 500 MPa at 0 °C were significantly higher (P < 0.05) than oysters HHP treated at 300 MPa at 0 °C in lipid oxidation values. The highest pressure (500 MPa) treatment in this study, significantly (P < 0.05) decreased unsaturated fatty acid percentage compared to control. The glycogen content of control oysters at 3 wk was significantly higher (P < 0.05) when compared to HHP treated oysters [300 MPa, (RT); 450 MPa (0 °C); and 500 MPa (0 °C)]. HHP treatments of oysters were not significantly different in pH, percent salt extractable protein (SEP), and total lipid values compared to control. Based on our results, HHP prolongs the physical, microbial, and chemical quality of oysters.     

Changes in tannin solubility and microstructure of high hydrostatic pressure–treated persimmon cubes during storage at 4 °C

Condensed tannins are important bioactive compounds largely present in persimmon (Diospyros kaki L.f.). The aim of this work was to study the effect of the structural changes occurred during refrigerated storage in persimmon cubes treated with high hydrostatic pressure (HHP) on the solubility and location of tannins, and some physicochemical properties. Persimmon cubes were submitted to 200 MPa for 3 and 6 min at 37 °C and stored at 4 °C for 28 days. The microstructural study was carried out by low-temperature scanning electron microscopy, light microscopy and transmission electron microscopy. The physicochemical properties studied were total soluble tannins (TST), total soluble solids (TSS), pH, lightness, firmness and cohesiveness. Microstructural studies showed that HHP treatment causes cell wall and membrane disruption in persimmon tissue. Retraction of the tonoplast and loss of cell turgor were greater as the storage time increased. Precipitated tannins inside and outside the cells and a progressive separation of adjacent cells during the storage time could be observed. Significant (P < 0.05) decreases in TST, TSS and lightness as well as a significant (P < 0.05) increase in pH took place in HHP-treated samples after 7 days of storage. Samples treated for 3 min showed higher firmness than the rest of the samples during the whole storage period, whereas HHP-treated samples showed higher cohesiveness than the control samples. The effects of HHP treatments and later storage at 4 °C on microstructure, tannin solubility and extractability, and some physicochemical properties of persimmon cubes depend on the treatment conditions and the storage time. HHP treatment might decrease persimmon astringency as well as increase bioactive compounds accessibility.     

Functional, Sensory, and Microbiological Properties of Restructured Beef and Emu Steaks

Beef and emu steaks were restructured with 5% fibrinogen/0.25% thrombin (F), 0.5% algin/0.5% calcium lactate (A), or 0.5% phosphate/1.5% salt (P). P and A treatments had higher cooked binding strengths and cook yields than the F treatments (P < 0.05). The pH and cook yields of restructured emu were higher than beef (P < 0.05). Binding strength of emu was lower than beef in all binding systems (P < 0.05). F solution had an aerobic plate count (APC) of 39,000/g and increased the microbial count in restructured emu steaks from 940 to 7500/g (P < 0.05). Cooking to 60°C reduced APC to < 250/g (P < 0.05) with progressively greater bacterial kill after cooking to 66°C or 75°C.     

Development of Meat Snack Dips: Chemical, Physical, Microbiological and Sensory Characteristics

Snack dips containing 50% ham, 26% bacon or 28% pepperoni in combination with sour cream, unflavored yogurt and tofu were developed. The developmental phases of the study were discussed in relation to ingredient and meat flavor selection, formulation and sensory evaluation. Microbiological, chemical and physical analyses of the new products indicated that the meat-containing snack dips were stable and safe under storage conditions simulating wholesale (3 wk 2-4°C), retail (10 days, 5°C, household (10 days, 8-10°C) and longer-than-normal temperature abuse (12 and 24 hr, 24-25°C).     

Nonvolatile taste compounds in cooked Chinese Nanjing duck meat following postproduction heat treatment

Abstract: Taste‐active compounds, including free amino acids, succinic acid and 5′‐nucleotides, and chemical components including moisture, pH, protein, crude fat, and sodium chloride were evaluated in cooked and packaged Chinese Nanjing ducks following heat treatments including control, 99 °C for 40 min, 108 °C for 20 min, 92 °C microwave followed by water heating, 95 °C for 30 min, 121 °C for 25 min. Heat treatment decreased (P < 0.05) the content of Alamine and moisture and reduced the pH value in muscle, but increased (P < 0.05) the protein and 5′‐nucleotides content. The 99 °C group had a significantly lower crude fat content compared with other groups (P < 0.05). The succinic acid content in the control group was significantly higher than in the 121 °C group (P < 0.05). Groups treated at higher temperatures (108 °C, 121 °C, and microwave) had similar equivalent umami concentrations and 5′‐nucleotides, free amino acids content, as well as the derived bitter and sweet taste components compared with the groups treated at lower temperatures. It can be speculated that these differences account for the enhanced flavor of the meat in the 99 °C, 108 °C, 121 °C, and microwave groups compared with the untreated control. Therefore, heat treatment at lower temperature after packaging may prolong product shelf life without any detrimental effects on taste. The results of this study indicate that it is important to use lower temperatures in this type of food processing. However, it may be possible to modify the primary processing steps to improve the content of umami‐like taste compounds such as 5′‐nucleotides. Practical Application: Heat treatment of packaged products is an effective method for eradication of microbes, therefore increasing the shelf‐life. However, such treatment can result in major changes in the sensory perception of meat products, particularly the formation of off‐flavors. This study investigated changes in taste‐active compounds in duck meat following a number of types of heat treatment.