MICROBIOLOGICAL AND SENSORY ANALYSES OF REFRIGERATED CATFISH FILLETS TREATED WITH ACETIC AND LACTIC ACIDS

The influence of acetic acid (AA) and/or lactic acid (LA) dips on microbial numbers, pH, and sensory scores of catfish fillets was assessed during storage at 4C. Fillets were treated by dipping in 4C AA and/or LA solutions for 0–60s. Fillets treated with either 3–4% AA or 2% AA and 2% LA for 30–60s suppressed growth of aerobic microorganisms for 4 days and extended shelf-life to 16 days. Treatment with either 3–4% LA or 1% AA and 1% LA for 5–60s prolonged microbiological shelf life to 12 days. AA had greater antimicrobial activity than LA. Fillets treated with AA alone or combinations of AA and LA were liked less by sensory panels than controls due to acidic odor and flesh discoloration. Thus, concentrations of AA or LA greater than 2% or exposure times greater than 30s are not recommended for catfish fillets.     

SENSORY AND OBJECTIVE EVALUATION OF A RESTRUCTURED BEEF PRODUCT

A study was undertaken to determine the effect of connective tissue, flake size and NaCl level on the texture of restructured beef steakettes; to examine the effect of these factors on the acceptability of restructured steakettes; and to develop sensory and instrumental texture profiles of the product. Restructured beef steakettes were manufactured with two levels of connective tissue (high, low), three flake sizes (3 mm, 6 mm, 13 mm) and three NaCl levels (0.25%, 0.50%, 0.75%). The textural attributes of these products were measured by a trained sensory panel and by objective measures of compression texture profile analysis, Warner-Bratzler shear and three tensile tests. Most sensory texture attributes could be predicted accurately using instrumental methods. Reduction of the sensory attributes by Principal Components Analysis revealed two underlying dimensions of connective tissue and bind strength. A consumer panel rated steakettes manufactured with 6 mm flakes and 0. 75% NaCl at either connective tissue level to be the most acceptable of the 18 products manufactured for this study.     

MICROBIAL, INSTRUMENTAL COLOR AND SENSORY CHARACTERISTICS OF GROUND BEEF PROCESSED FROM BEEF TRIMMINGS TREATED WITH POTASSIUM LACTATE, SODIUM METASILICATE, PEROXYACETIC ACID OR ACIDIFIED SODIUM CHLORITE AS SINGLE ANTIMICROBIAL INTERVENTIONS

Beef trimmings, inoculated with Escherichia coli (EC) and Salmonella typhimurium (ST), were treated with 3% potassium lactate (K-L), 4% sodium metasilicate (NMS), 0.1% acidified sodium chlorite (ASC) or 0.02% peroxyacetic acid (PAA) prior to grinding. The ground beef packages were sampled at 0, 1, 2, 3 and 7 days of simulated retail display. All treatments reduced ( P <  0.05) EC, coliforms and aerobic plate counts up to and some in excess of 1 log and ST count  ≥  1.5 logs. Sensory panelists found ground beef from all treatments to generally be similar ( P >  0.05) to the control in odor and similar ( P >  0.05) in color for the K-L and NMS treatments during initial display. Instrumental color results indicated that K-L, NMS and PAA were similar ( P >  0.05) in redness ( a* ) to the control. These findings indicated that use of tested antimicrobial agents can reduce microbial numbers with little impact on sensory odor and color characteristics.

PRACTICAL APPLICATIONS

Although antimicrobial interventions have shown promising results in decontaminating meat products, there are only a limited number of antimicrobial products that can be used without causing adverse effects on quality characteristics of the final product. Consumers often discriminate against discolored meat products, and thus any deleterious effects on color and other quality attributes in decontaminated products will lead to a negative economic impact. The outcome of this research will provide information on selection of antimicrobial agents that will maximize ground beef safety without causing deleterious effects on quality attributes. Application of suitable antimicrobial interventions at the end of a production line will be advantageous to supply ground beef with increased shelf-life and decreased or no risk for illnesses caused by pathogens.     

SHELF-LIFE OF COLESLAW MADE FROM CABBAGE TREATED WITH GASEOUS ACETIC ACID

Coleslaw containing 25% mayonnaise was formulated with untreated cabbage (control) and cabbage fumigated with two levels of gaseous acetic acid: 0.08 mL and 0.50 mL/100 g cabbage. A device consisting of a rotating barrel and vaporizing chamber was used to fumigate the shredded cabbage. Populations of aerobic microorganisms in coleslaw made from untreated cabbage reached 10⁸ cfu/g after 15 days in storage at 5C. Growth of lactic acid bacteria was extensive and in some cases this group was chiefly responsible for spoilage. Microorganisms were not detected in coleslaw made from cabbage fumigated at higher levels of acetic acid during 22 days in storage. Mayonnaise had a lethal effect on the microflora of cabbage, and fumigation with acetic acid prior to formulation of coleslaw increased the effect. The color of coleslaw was not affected by fumigation but CO₂ production during storage was reduced.     

SENSORY EVALUATION OF CANNED MEAT-BASED FOODS SUPPLEMENTED WITH DRIED DISTILLERS GRAIN FLOUR

Dried distillers grain (DDG) flour was evaluated as an ingredient in canned meat-based foods — beef stew, chili no beans, and hot dog sauce. DDG can be supplemented up to 2.0% in beef stew, chili no beans, and hot dog sauce without significant changes in organoleptic characteristics such as appearance, flavor, mouthfeel, and overall acceptability. DDG may be used as a thickening agent along with modified starch in beef stew. In chili no beans and hot dog sauce, DDG can partially or completely replace texturized vegetable protein, soy or wheat flour.     

SENSORY ATTRIBUTES AND RETAIL DISPLAY CHARACTERISTICS OF PASTURE- AND/OR GRAIN-FED BEEF AGED 7,14 OR 21 DAYS

Strip loin steaks were removed from steer carcasses fed on; (1) wheat-rye-grass pasture only, (2) wheat-ryegrass pasture followed by grain feeding, or (3) grain feeding. The steaks were analyzed for sensory panel attributes, Warner-Bratzler shear force and storage and display life. Steaks from pasture-fed steers were similar (P>.05) to steaks from grain-fed steers in sensory tenderness and connective tissue amount. Steaks from pasture-fed steers had similar (P>.05) shear force values to steaks from grain-fed steers. Off flavor incidence was greater (P<.05) in steaks from steers on pasture only than from steers on grain and pasture/grain. No differences (P>.05) due to treatment were found in visual color and discolor scores. The C.I.E. a* values showed steaks from steers fed pasture only and pasture/grain retained higher (P<.05) redness values than steaks from steers grain-fed during the 10 day display period. The results indicate pasture finishing systems could be as effective in maintaining beef tenderness and color shelf-life characteristics as grain finishing systems.     

MICROBIOLOGICAL AND SENSORY EVALUATION OF COOKED ROAST BEEF PACKAGED IN A MODIFIED ATMOSPHERE

Sliced cooked roast beef was packaged in a modified atmosphere (MA) consisting of 75% CO2, 15% N2 and 10% 02 and stored at 4.4°C for 42 days to evaluate the MA's effectiveness at controlling the outgrowth of Pseudomonas fragi, Clostridium perfringens, Staphylococcus aureus and Salmonella typhimurium after inoculation. Additionally, a taste panel was conducted to monitor the effects of modified atmosphere packaging (MAP) on sensory parameters of uninoculated samples. P. fragi was able to grow only to a limited extent in the MA, but grew to high numbers in air. The three pathogens were unable to grow in the MA, probably due to the effects of temperature. Numbers in S. typhimurium and C. perfringens declined more rapidly in the MA than in air but S. aureus numbers did not decrease in either atmosphere. High numbers of molds were recovered from the uninoculated samples stored in air but none were recovered from MAP samples. Sensory analysis indicated that most product deterioration occurred within the first 7 days of storage.     

EVALUATION OF THE PHYSICAL AND SENSORY PROPERTIES OF JERKY PROCESSED FROM BEEF HEART AND TONGUE1

Eighteen beef jerky formulations (nine treatments, 3 muscle types X 3 cooking times X 2 replications) were prepared from USDA Good top rounds, hearts, and tongues obtained from a commercial source. Muscles were sliced, cured 3 days and cooked at 64 Cfor 12, 14 and 16 h. All treatments were evaluated for visual, sensory, chemical and cost analysis. Jerky produced from beef heart reduced final cost by 43%; however, visual and flavor properties of beef heart jerky were less desirable than jerky prepared from top round. Tongue jerky products were high in fat, extremely expensive and would be undesirable for today's health-oriented consumer. Top round beef jerky was the most desirable based upon sensory analysis, but heart jerky was highest in protein and lowest in fat. Further work may increase the possibility of reducing jerky costs by improving the color and flavor of beef heart jerky.     

乙酸-微波预处理法提取辣椒素的研究

采用微波辅助提取方法,以乙酸为提取剂从辣椒粉中提取辣椒素.对影响提取效率的因素进行了优化,获得了最佳提取条件:每g辣椒粉以1 mL,10%乙酸为气化剂,浸润15 min,微波功率480 W,处理90 s,用 8 mL,50%乙酸在50℃下浸取50 min.     

EFFECT OF ENZYMATIC TENDERIZATION, BLADE TENDERIZATION, OR PRECOOKING ON SENSORY AND PROCESSING CHARACTERISTICS OF BEEF BACON

The objectives of this study were to evaluate the effects of enzymatic tenderization, blade tenderization, or precooking on the visual and palatability attributes of beef bacon. Injection of 30 ppm bromelin into beef plates processed into beef bacons significantly (P < 0.05) reduced visual binding and appearance scores compared with the control, 10 ppm- and 20 ppm-injected products. Bacons produced from Choice grade carcasses were saltier, more bacon flavored, softer, higher in fat content, and had lower shear force values than bacons produced from Utility grade carcasses. Precooking of injection-cured beef bacons decreased slice integrity, saltiness, and flavor intensity and increased toughness, shear force, and off-flavor compared with the controls.     

INSTRUMENTAL AND SENSORY MEASUREMENT OF BEEF PATTY AND SAUSAGE TEXTURE

Beef sausages and beef patties of different texture were produced by varying the fat content in the raw mix over the range 5–30%. Batter shear stress and strain increased linearly with increased fat level (P<0.09 and 0.001, respectively). Although batter shear stress was not related to sensory scores, shear strain was directly related to moistness and inversely related to grittiness scores (P<0.05). Batter sensory moistness increased and firmness and grittiness deceased linearly with fat content (P<0.001). Changes in fat content did not affect the peak force of cooked patties, and there were poor correlations between patty peak force and sensory scores. Patty juiciness and softness increased and patty cohesiveness and chewiness decreased with fat content (P<0.001). Batter cook yield increased and patty cook yield decreased with increasing fat level (P<0.001). Sensory scores, using trained panelists, were more sensitive to the effect of fat content on patty and sausage texture than instrumental measurements.