QUALITY CHARACTERISTICS OF LOW-FAT FRANKFURTERS MANUFACTURED WITH POTATO STARCH, FINELY GROUND TOASTED BREAD AND RICE BRAN

Low-fat frankfurters (10% fat, 13% protein) were produced with 3.0% potato starch, finely ground toasted bread and rice bran or their combination. No differences (P > 0.05) were found in processing yield and purge accumulation among treatments of tested ingredients. Potato starch (3.0%) significantly increased the lightness, hardness and skin strength of low-fat frankfurters. Finely ground toasted bread had the highest scores for visual color, external redness, flavor intensity and overall acceptability and improved (P < 0.05) skin strength of frankfurters in comparison to potato starch. Low-fat frankfurters with 3.0% rice bran had the same (P>0.05) visual color scores, redness and textural properties as those produced with potato starch and toasted bread, but lower (P < 0.05) flavor intensity and overall acceptability and were judged as "just acceptable". Decreasing the rice bran from 3.0 to 1.5% and using it in combination with toasted bread (0.75%) and potato starch (0.75%) had an insignificant effect on the flavor intensity and overall acceptability of low-fat frankfurters.     

EFFECTIVENESS OF SELECTED ADJUNCTS ON PROCESSING AND SENSORY CHARACTERISTICS OF EXTRA LEAN FRANKFURTERS

The effects of maximum levels of selected additives in extra lean frankfurters (<3% fat) were studied. Seven treatments, with four replications each, were evaluated at three time periods (0, 30 and 60 days) in a randomized complete block design. The treatments consisted of: control; kappa-carrageenan; hydroxypropyl methylcellulose (HPMC); high methoxy pectin (pectin); an acid modified food starch; sodium lactate; and acid enzyme deheated mustard. All treatment frankfurters had higher (P<0.05) yields than the controls. The pectin product had an unacceptable extremely soft, smooth pasty texture. Pectin and HPMC products had the lowest (P<0.05) purge at 60 days. In general, the addition of some appropriate additive or additives to low-fat sausage products appears to be appropriate to increase processing yields, reduce cost and help bind free water so long as the additive or additives do not adversely affect other properties of the product.     

EFFECT OF PROCESSING AND STORAGE CONDITIONS ON THE MICROFLORA OF CLOSTRIDIUM PERFRINGENS-INOCULATED FRANKFURTERS

SUMMARY: The growth support potential of frankfurters for Clostridium perfringens was determined. Inoculated emulsions were stuffed into glass tubes and processed so that they reached an internal temperature of 68–69°C in 30–48 min. The tubes were sealed with agar plugs and rubber stoppers to simulate vacuum-packaging conditions. Total aerobic and anaerobic bacterial counts in uninoculated raw emulsion were 1 to 3 log cycles higher when petri dishes were incubated at 23°C as opposed to 37°C. The low-temperature-growing mesophiles and psychrotrophs were destroyed during processing. The 37°C counts were reduced 1 log cycle and the 23°C counts, 2 to 3 log cycles. Clostridium perfringens reproduced rapidly in frankfurters at 37 and 23°C, more slowly at 15 and 12°C, and not at all during 2 wk of storage at 10° or 4 wk at 0–5°C. Clostridium perfringens made up 2.5–10% of the total anaerobic count at 0 time but became the dominant organism during the storage at all temperatures permitting growth.     

CHARACTERISTICS OF LOW-FAT FRANKFURTERS MANUFACTURED WITH MODIFIED BEEF CONNECTIVE TISSUE

A 3 fat level (8%, 16% and 24%, finished weight basis) × 5 modified connective tissue level (0%, 10%, 20%, 30% and 40%, meat block basis) complete factorial design was employed to characterize frankfurters manufactured with modified beef connective tissue (MCT). Thermal processing yields improved 2–3% with the addition of 20% or more MCT. Level of MCT did not affect average consumer cook yields. Kramer Shear parameters were higher with higher levels of MCT. Frankfurter cohesiveness declined with an increase in MCT. A consumer panel found low-fat frankfurters to be less desirable in almost all traits than high fat products. Frankfurters with 10–20% MCT were as desirable as controls (0% MCT). Frankfurter external and internal color was lighter as level of MCT increased. Frankfurters with MCT were rated as desirable by a consumer sensory panel, and had color and yields similar to higher fat products.     

EFFECT OF THERMAL PROCESSING ON STRUCTURE AND RHEOLOGICAL PROPERTIES OF CARRAGEENAN/CAROB GUM GELS

Optical rotatory dispersion and rheological studies have been used to investigate changes in carrageenan and carob gels on thermal processing. A synergistic effect was observed on the gel strength of both unprocessed and heat processed carrageenan carob gels when compared to gels without carob, although a lower gel strength was measured after processing. The reduction in strength of gels on heat processing appears to be due mainly to the depolymerisation of the network chains while the crosslinks of the gel are largely unaffected.     

EFFECT OF SMOKEHOUSE TEMPERATURE, HUMIDITY AND AIR VELOCITY ON RATE OF HEATING AND QUALITY OF FRANKFURTERS

The effects of air velocity, relative humidity, temperature and presence of glucono delta lactone (GDL) on the quality of frankfurters, were evaluated. Rate of heating was inversely proportional to rate of weight loss during processing. High humidity processes at slow air flows had the fastest heating rates; however, quality was unacceptable because of fat separation and pale color. A process where the smokehouse temperature was slowly increased by 6°C increments, and where a low relative humidity and high air flow were used, gave the best quality. Color and texture was more desirable on products having higher shrink. The presence of GDL had no effect on the final color of products processed under the same conditions; however, maximum color appeared to develop earlier in samples containing GDL.     

EFFECT OF TEMPERATURE AND WATER CONCENTRATION DURING PROCESSING ON FOOD QUALITY

Water content and temperature during food processing have a pronounced influence on the rates of those changes in food properties which are the object of the process such as reduction in water content or sterilization. However, they also strongly influence adverse side effects such as browning, loss of nutrients or shrinking. When the effects of temperature and water concentration on the process rates of the desired and adverse processes are known, the processes can be optimized. An example of the optimization procedure is given for the spray drying of heat-labile aroma containing liquid foods. Both temperature and moisture content of the droplets change with time in spray-drying. In a second example a new and simple calculation method is introduced for the optimization of quality retention in the sterilization of packed foods.     

低脂Mozzarella干酪品质的研究

通过设定不同脂肪含量,研究低脂Mozzarella干酪的蛋白水解、TPA质构、功能特性和微观结构.结果表明,低脂Mozzarella干酪的各个指标较全脂Mozzarella干酪均有所降低.其中,脱脂Mozzarella干酪的品质明显降低,接受性差;中脂Mozzarella干酪品质接近于全脂Mozzarella干酪,部分脱脂Mozzarella干酪介于脱脂和中脂Mozzarella干酪之间,具有可接受性.     

QUALITY CHARACTERISTICS OF MEAT BATTERS AND FRANKFURTERS CONTAINING WHEAT GERM PROTEIN FLOUR1

Frankfurters were extended with wheat germ protein flour (WGPF) at 3.5, 5.0. and 7.0%. Water added during formulation was increased by 2% for every 1% of WGPF added. Batters containing WGPF had higher pH and adhesiveness values. Viscosities of the batters were not affected by addition of WGPF. Batters containing WGPF had lower cooking losses, and lower percent water and fat separated. Positive effects, such as lower cooking losses, higher processing yields and lower percent fat, were not consistent at levels of WGPF beyond 3.5%, probably because of higher levels of added water. Total yields of the samples containing WGPF were higher than those of control samples. No differences were observed in protein and amino acid contents of samples. Lower fat content was found in samples extended with 7.0% WGPF. Frankfurters containing WGPF had lower shear force and firmness values. Differences in color of frankfurters were also observed.     

EFFECT OF LUBRICATION ON THE COMPRESSION BEHAVIOUR OF CHEESE AND FRANKFURTERS

Cylindrical samples of cheese and frankfurters were subjected to a 50% uniaxial compression between flat plates and artificial molars, mounted on a Texture Analyser, operating at two speeds, with and without lubrication. At both speeds and with both types of probe the maximum force was less for the lubricated probes than the unlubricated probes. In all cases the maximum force recorded at the higher speed was greater than at the lower speed and greater when plates were used than when teeth were used. Through observations made during the testing and from photographs taken, it was concluded that the frictional effect of the cusps on the molar teeth was greater than the effect of lubrication. Observations made when samples were compressed between molar teeth in the mouths of panellists confirmed the conclusion that compression of foods in the mouth follows the nonlubricated pattern despite the lubrication provided by saliva.     

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)