COMPARATIVE STUDY OF SHELF-LIFE OF FRANKFURTERS CONTAINING PLANT PROTEIN ADDITIVES1

Soy flour (SF), soy concentrate (SC), soy isolate (SI) and corn germ protein flour (CGPF) were incorporated in frankfurters. The sensory analysis, chemical, and microbiological tests were conducted to investigate the effect of plant proteins on stability during vacuum-packaged storage. No significant difference in meaty aroma was found between all samples after 45 days storage. Atypical flavor and aroma of all samples, including the all-meat control increased (P < 0.05) after 45 days storage. A tendency was found of increase in atypical aroma and flavor with increase in total volatile nitrogen values and total psychrophiles during storage. Salty flavor increased with storage time in experimental samples, but juiciness decreased. Samples containing SF and SC had higher total volatile nitrogen than SI and CGPF containing samples at 2, 30 and 45 days of storage. No significant differences were found in TBA values between tested samples, except higher TBA values for SI containing samples. There was no significant difference among samples in total psychrophilic counts.     

Cottonseed Proteins in Frankfurters: Effect on pH, Cured Color, and Sensory and Physical Properties

Frankfurter-type sausages were made in which 5%, 10%, or 15% of the meat was replaced with the following cottonseed-derived protein products: genetically glandless cottonseed flour (CF); liquid cyclone processed deglanded cottonseed flour (LCPC); genetically glandless cottonseed storage protein isolate (CI). All-meat controls (0% cottonseed protein additive) were formulated at each replacement level with fat contents equivalent to those of the cottonseed protein-added frankfurters. Compared to all-meat controls, frankfurters made with increasing levels of cottonseed proteins generally had higher pH values, less cured color, less firmness of skin, softer texture, and were less desirable as judged by sensory panels. At the 10% and 15% replacement levels, frankfurters containing LCPC, had significantly (P < 0.05) lower scores for external and internal visual color, overall satisfaction and bioyield and rupture force values than did Cl-added frankfurters. Simple correlation coefficients suggest that significantly (P < 0.05) correlated responses exist within and across replacement levels between pH and sensory panel scores, Instron values and visual color scores.     

Potato Starch and Flour in Frankfurters: Effect on Chemical and Sensory Properties, and Total Plate Counts

Potato starch and flour were examined as possible constituents in frankfurter formulations. Frankfurters manufactured with 3% potato starch or 1.5% potato starch plus 1.5% potato flour in place of 3% wheat flour normally used as a binder, and stored at 4–5°C for 28 days did not differ significantly in percent shrink, water, protein, fat, ash or salt. Residual nitrite levels decreased during the storage period. Total plate counts reflect residual nitrite levels since the frankfurters (3% starch) with the lowest nitrite concentration also had the greatest number of bacteria (6.4 × 10⁶/g) on day 28. Frankfurters formulated with 1.5% potato starch plus 1.5% potato flour were rated more tender and more juicy than those made with 3% potato starch (P≤0.05 and P≤0.01) and 3% wheat flour (P≤0.01 and P≤0.01), respectively. Fresh potato starch and wheat flour franks did not differ from each other in either characteristic but after one week's storage the potato starch samples were rated more tender (P≤0.05) and more juicy (P≤0.01). Less force was required to shear the frankfurters formulated with 3% potato starch.     

Staling of cake prepared from rice flour and sticky rice flour

MiGao, prepared from rice flour and sticky rice flour, is a kind of steam cooked Chinese cake. Staling of MiGao resulted in loss in texture and eating quality. Moisture content, water activity, texture, differential scanning calorimetry thermograms and sensory quality of MiGao, were monitored and were found to be significantly affected by cake staling when stored at room temperature for up to 5 days. The moisture content decreased after 2 days of storage and during the following days the crumb moisture content remained practically unchanged. Firmness was developed mainly during the first day of storage, remained at a similar level from day 2 to 3 and increased slightly after the third day of storage. A decrease in sensory quality and acceptability of the MiGao was observed during storage. Differential scanning calorimetry was used to follow changes of starch retrogradation in MiGao crumb. Amylopectin recrystallisation in MiGao continued to increase during storage.     

Reduction of Listeria monocytogenes populations during exposure to a simulated gastric fluid following storage of inoculated frankfurters formulated and treated with preservatives

The effect of a simulated gastric fluid (adjusted to pH 1.0 with HCl) on Listeria monocytogenes, inoculated postprocessing on pork frankfurters formulated with sodium lactate (SL) and sodium diacetate (SD) and not dipped or dipped in solutions of lactic acid or acetic acid, was evaluated during storage of the frankfurters at 10 degrees C for 40 days. Pork frankfurters containing 1.8% SL, 0.25% SD, 1.8% SL+0.125% SD, or 1.8% SL+0.25% SD were inoculated with 10(2)-10(3) CFU/cm2 of a 10-strain preparation of L. monocytogenes and were not dipped or dipped for 2 min in solutions of 2.5% lactic or acetic acid before they were vacuum-packaged and stored. Survival of L. monocytogenes was determined after exposure of frankfurters for 0, 20, 40, and 60 min to the simulated gastric fluid after storage for 0, 10, 20, 30, or 40 days. Growth of L. monocytogenes on frankfurters formulated with antimicrobials was inhibited in the order control 相似文献   

Influence of Bacterial Cellulose (nata) on the Physicochemical and Sensory Properties of Frankfurter

The physicochemical and sensory characteristics of pork frankfurters containing different levels (10% to 30%) of bacterial cellulose (nata) were evaluated. Emulsion stability of the raw meat batter decreased with the addition of nata. For nata‐added treatments, increasing levels of nata in frankfurters resulted in decreased textural hardness and shear values. Sensory results indicated that N10 and N20 had significantly higher firmness scores than N30 and control. However, juiciness score did not differ for all treatments. Incorporation of nata at lower levels (10% to 20%) did not have detrimental effects on the physicochemical, textural, sensory, and microbiological properties of regular‐fat frankfurters. Addition of a higher level (30%) of nata essentially produced comparable sensory properties to the control, but lower levels of nata in frankfurters yielded higher sensory firmness and instrumental hardness values. Based on the composite results, manufacture of regular‐fat frankfurter containing 10% to 20% high‐fiber nata resulted in product quality comparable to the control.     

Protein profile and malt activity during sorghum germination

BACKGROUND: The effect of germination time on major sorghum macromolecules was followed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS‐PAGE), Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy. Sorghum flour was also incubated with sorghum malt to evaluate amylase and protease activities. RESULTS: The SDS‐PAGE results showed that levels of high‐molecular‐weight aggregates, β monomer and γ and α monomers increased by 120.5, 20.3 and 12.7% respectively during the first few days of germination. This behaviour shows the enhancement of prolamin extractability and concentration in sorghum as a result of starch degradation. After the third day, proteins suffered degradation by intrinsic proteases. FTIR spectroscopy showed a gradual decrease in lipid and protein levels and starch structural changes during the germination period. These modifications are due to intrinsic lipases, proteases and amylases. Sorghum flour was incubated with different malt samples resulting from 0–7 days of germination. It was found that a 5 day malt led to a sixfold increase in carbohydrate digestibility and a fourfold increase in free amino acid content. CONCLUSION: A 5 day sorghum malt is the best inoculum for porridge preparation, representing an inexpensive, effortless and culturally acceptable way to prepare weaning foods at domestic and industrial levels. Copyright © 2008 Society of Chemical Industry     

CORN GERM PROTEIN IN FRANKFURTERS: TEXTURAL,COLOR, AND SENSORY CHARACTERISTICS AND STORAGE STABILITY1

Textural properties, water holding capacity, color, sensory characteristics, and storage stability of frankfurters containing hexane-defatted corn germ protein (CGP) as a meat extender were studied. CGP was incorporated at 2 and 3% levels as a powder or a preswelled slurry. Batter viscosity and shear force values of frankfurters were increased by the preswelled CGP. The redness values of the experimental samples with 2 and 3% CGP added as a powder were less than those of controls. There were no significant effects of CGP incorporation or its preswelling on the initial sensory properties of frankfurters. Meaty flavor and aroma and off-flavor acceptability decreased during 45 days of storage. Off-flavor and off-aroma of frankfurters showed a slight increase with time in storage. Total volatile nitrogen and nonammonia amino nitrogen of experimental and control frankfurters were not significantly different.     

Effect of preincubation of sorghum flour with enzymes on the digestibility of sorghum gruel

A low-tannin sorghum cultivar M-35-1 was used in this study. Sorghum was germinated for 6 days and protease and amylase activities were measured every 24 h. Results showed that the 5th day germinated sorghum had a higher protease activity and a lower amylase activity. Sorghum flour was incubated for 30 min with the extract from germinated sorghum or with 0.01, 0.05 or 0.1 mg ml⁻¹ papain or trypsin prior to cooking in water. Results showed increase in in vitro protein digestibility (IVPD) with the 5th day germination extract. Pretreatment of sorghum flour with small amounts of papain or trypsin (0.01 mg ml⁻¹) improved the IVPD without affecting the paste viscosity, whereas the germinated sorghum extract led to very low paste viscosity. ©     

Effect of dietary fish oil on fatty acid composition, lipid oxidation and sensory property of chicken frankfurters during storage

Broilers fed with three levels of fish oil (0, 2 and 4%) for 6 weeks were used in the manufacture of chicken frankfurters. The meat samples were vacuum-packed and stored at 0°C for 0, 10, 20 and 30 days. Cooking yield, proximate and fatty acid composition, lipid oxidation, microbial and sensory properties of the meat products were measured. Cooking yield, moisture, fat, protein, ash and cholesterol contents of frankfurters were not affected (P>0.05) by levels of dietary fish oil. Frankfurters processed from chickens fed diets enriched with 2 and 4% of supplemental fish oil had a higher (P<0.05) level of n-3 fatty acids (eicosapentaenoic acid and docosahexaenoic acid), but had a lower level of n-6 fatty acids (P<0.05) than the controls (0% fish oil). TBA values and pH values of meat samples were not affected (P>0.05) by levels of supplemental fish oil in the diets, however, pH values of the vacuum-packaged chicken frankfurters decreased (P<0.05) as the storage time increased. No differences (P>0.05) in total anaerobic plate counts were observed among the fish oil treatments during storage. Supplementation of 2 and 4% fish oil in the diets did not increase (P>0.05) the intensity of fishy flavor in chicken frankfurters.     

Effect of malt pretreatment on phytate and tannin level of two sorghum (Sorghum bicolor) cultivars

The seeds of two cultivars of Sudanese sorghum (Sorghum bicolor), namely Wad Ahmed and Tabat, were germinated for 4 days to obtain 1‐, 2‐ and 4‐day‐old malts. Sorghum malt (5% and 10%) was added to sorghum flour. The mixtures were incubated at 30 °C with shaking for 30, 60, 90 and 120 min. Malting loss was very slight for both cultivars and for all incubation periods. Phytic acid and tannin contents were assayed for all treatments. The results revealed that phytate and tannin contents were significantly (P ≤ 0.05) reduced when sorghum flour was pretreated with malt. When a mixture containing 10%, 4‐day‐old malt and sorghum flour was incubated for 120 min, it significantly (P ≤ 0.05) reduced phytate and tannin contents by 92% and 98%, respectively, for Wad Ahmed cultivar, while for Tabat they were reduced by 93% and 96%, respectively. The rate of reduction of phytate and tannin content increased with incubation time and malt age and concentration.     

Effects of fat level and maltodextrin on the functional properties of frankfurters formulated with 5, 12 and 30% fat

The effects of fat level (5, 12 and 30%) and maltodextrin on emulsion stability, cook loss, colour, texture and sensory characteristics of frankfurters were investigated. Three fat levels (5, 12 and 30%) were formulated containing added maltodextrin. For each fat level a control was prepared without added maltodextrin giving a total of 6 treatments (3×2 factorial design). Reducing the fat from 30 to 5% increased cook loss and decreased emulsion stability. Panellists detected an increase in juiciness and a decrease in overall texture, overall acceptability when the fat level was reduced from 30 to 5%. Instron texture profile analysis showed a decrease in hardness, chewiness and gumminess and an increase in springiness with decreasing fat level. Maltodextrin addition caused a significant decrease in cook loss of the frankfurters but also decreased the emulsion stability. An interactive effect (P<0.05) occurred between fat level and maltodextrin resulting in no significant difference in hardness, gumminess and chewiness values when maltodextrin was present in the reduced-fat (5 and 12%) frankfurters. Saltiness, overall flavour intensity, overall texture and overall acceptability were unaltered (P>0.05) by maltodextrin. The results indicate that maltodextrin can be used as a suitable fat replacer since it offset some of the changes brought about by fat reduction, decreasing cook loss and maintaining a number of textural and sensory characteristics of the frankfurters.     

FRANKFURTERS EXTENDED WITH WHEAT GERM PROTEIN: SENSORY PROPERTIES AND CONSUMER RESPONSE1

In this study, 103 consumers evaluated the sensory acceptance of frankfurters extended with wheat germ protein flour (WGPF). Consumers as a whole did not perceive any differences in the attributes of appearance, flavor, texture, and overall acceptance. However, samples with WGPF were scored lower for intensities of hot dog flavor and spiciness. Perception of intensities of attributes varied depending on age, frequency of consumption, and whether the consumer was male or female. WGPF did not influence the overall acceptance of the product. A trained panel found a difference in smoky flavor due to treatment and a weak difference in smoky aroma and flavor due to storage. Trends suggested an effect due to increasing levels of WGPF on aroma and flavor of frankfurters.     

PROPERTIES OF FRANKFURTERS PROCESSED WITH POTASSIUM AND SODIUM BICARBONATE

A study was designed to evaluate the use of low levels of sodium (0.25, 0.5, 1%) and potassium (0.25, 0.5%) bicarbonate on the sensory, microbial and functional properties of frankfurters. Both sodium and potassium bicarbonate resulted in higher pH values than control (no bicarbonate) on day 0 but differences diminished after storage at 4°C for 22 days. At the 0.5% level of addition, both sodium and potassium bicarbonate treatments had lower percent free water when compared to controls. The addition of high levels of bicarbonate resulted in diminished sensory properties; however, low levels had sensory characteristics in the acceptable range. No differences were detected between treatments for aerobic plate counts, anaerobic plate counts or yeast and mold counts. Results indicate an acceptable product can be produced using low levels of either sodium or potassium bicarbonate. The use of low levels of bicarbonate also results in beneficial changes of some physical properties.     

Effect of Sorghum Flour Addition on In Vitro Starch Digestibility,Cooking Quality,and Consumer Acceptability of Durum Wheat Pasta

Whole grain sorghum is a valuable source of resistant starch and polyphenolic antioxidants and its addition into staple food like pasta may reduce the starch digestibility. However, incorporating nondurum wheat materials into pasta provides a challenge in terms of maintaining cooking quality and consumer acceptability. Pasta was prepared from 100% durum wheat semolina (DWS) as control or by replacing DWS with either wholegrain red sorghum flour (RSF) or white sorghum flour (WSF) each at 20%, 30%, and 40% incorporation levels, following a laboratory‐scale procedure. Pasta samples were evaluated for proximate composition, in vitro starch digestibility, cooking quality, and consumer acceptability. The addition of both RSF and WSF lowered the extent of in vitro starch digestion at all substitution levels compared to the control pasta. The rapidly digestible starch was lowered in all the sorghum‐containing pastas compared to the control pasta. Neither RSF or WSF addition affected the pasta quality attributes (water absorption, swelling index, dry matter, adhesiveness, cohesiveness, and springiness), except color and hardness which were negatively affected. Consumer sensory results indicated that pasta samples containing 20% and 30% RSF or WSF had acceptable palatability based on meeting one or both of the preset acceptability criteria. It is concluded that the addition of wholegrain sorghum flour to pasta at 30% incorporation level is possible to reduce starch digestibility, while maintaining adequate cooking quality and consumer acceptability.     

Grape seed flour is a viable ingredient to improve the nutritional profile and reduce lipid oxidation of frankfurters

In this study, grape seed flour (GSF) obtained from wine by-products was incorporated into frankfurters at seven concentrations (0, 0.5, 1, 2, 3, 4, and 5%) and the effects occurred on physical, nutritional and sensory characteristics of the products were investigated. The colour values (L*, a* and b*) of frankfurters generally decreased (p < 0.05) on account of the increasing amount of GSF. The utilization of this flour also led to a decline in the oxidation level of the products (p < 0.05), probably due to its antioxidant content. The increment of GSF in the frankfurters enhanced the protein, total dietary fibre and water holding capacity of the treatments (p < 0.05). Although the level of GSF above 0.5% reduced overall acceptability, the frankfurters containing the level up to 2% received scores above the average. The evaluation of wine by-products in the production of healthier and functional frankfurters has been achieved by the study, but further research is necessary to improve palatability of the products.     

Control of Listeria monocytogenes with combined antimicrobials after postprocess contamination and extended storage of frankfurters at 4 degrees C in vacuum packages

Contamination of ready-to-eat foods, such as frankfurters, with Listeria monocytogenes, is a major concern that needs to be addressed in order to enhance the safety of these products. The objective of this study was to determine the effectiveness of combinations of antimicrobials included in the formulation of frankfurters against L. monocytogenes inoculated (10(3) to 10(4) CFU/cm2) on their surface after peeling and before vacuum packaging. In addition, the antilisterial effect of immersing the packaged products, prepared with or without antimicrobials, in hot (75 or 80 degrees C) water for 30 to 90 s was evaluated. Samples were stored at 4 degrees C for up to 120 days and periodically analyzed for pH and for microbial growth on tryptic soy agar plus 0.6% yeast extract (TSAYE) and PALCAM agar. Sodium lactate (1.8%; 3% of a 60% commercial solution) used alone inhibited growth of L. monocytogenes for 35 to 50 days, whereas when used in combination with 0.25% sodium acetate, sodium diacetate, or glucono-delta-lactone (GDL), sodium lactate inhibited growth throughout storage (120 days). Immersing packaged frankfurters in hot water (80 degrees C, 60 s) reduced inoculated populations of L. monocytogenes by 0.4 to 0.9 log CFU/cm2 and reduced its growth by 1.1 to 1.4 log CFU/cm2 at 50 to 70 days of storage in samples containing 1.8% sodium lactate alone. However, immersion of frankfurters containing no antimicrobials in hot water (75 or 80 degrees C) did not inhibit growth of the pathogen for more than 10 to 20 days, unless one frankfurter was placed per bag and heat treated for 90 s. These results indicate that the inclusion of 1.8% sodium lactate with 0.25% sodium acetate, sodium diacetate, or GDL in cured meat formulations may control L. monocytogenes growth during refrigerated (4 degrees C) storage. Additional studies are required to evaluate the effects of these combinations at abusive temperatures of storage, as well as on additional processed meat formulations and on the sensory quality and shelf life of products.     

添加蓝莓发酵汁对法兰克福香肠抗氧化及感官品质的影响

研究蓝莓发酵汁（fermented blueberry juice,FBJ）对法兰克福香肠脂肪和蛋白氧化的抑制能力以及对其感官品质的影响。将不同质量分数的FBJ加入法兰克福香肠中,研究其对香肠贮藏过程中硫代巴比妥酸反应产物含量和羰基含量的影响,以及对香肠色泽、pH值、质构和感官评分的影响。结果表明：添加质量分数2%、4%、6%的FBJ均能够有效抑制法兰克福香肠在加工和贮藏期间脂肪和蛋白的氧化,并且在贮藏后期效果优于添加质量分数0.05%异抗坏血酸钠的香肠（P＜0.05）;添加FBJ的法兰克福香肠红度值、黄度值均显著高于对照组（P＜0.05）,但是硬度显著低于对照组（P＜0.05）,弹性没有显著差异（P＞0.05）;此外,电子鼻和感官实验中,各FBJ组与对照组的风味能明显区分开,其感官评价结果也显著优于对照组,尤其是添加质量分数4% FBJ的法兰克福香肠综合评分最高。本研究结果证明FBJ是较好的抗氧化剂,可以有效抑制法兰克福香肠加工和贮藏过程中的脂肪和蛋白质氧化,同时能够改善法兰克福香肠的感官品质。     

ADDITION OF DRY- AND WET-MILLED CORN GERM FLOURS TO MODEL SYSTEM FRANKFURTERS OF THREE FAT LEVELS1

Chemical, physical and sensory properties of cooked frankfurters of three fat levels with 0 and 3.5% dry-milled corn germ (DMG) flour and 0 and 3.5% wet-milled corn germ (WMG) flour added were investigated. As fat level increased, cooking losses increased and Instron compression values decreased, in cooked frankfurters with DMG and WMG flours. Addition of DMG flour decreased fat content and lightness (L) and increased yellowness (b-value) of cooked frankfurters. Sensory evaluation indicated that DMG flour in frankfurters decreased tenderness, juiciness and cured flavor intensity. The addition of DMG flour increased chewiness of frankfurters. WMG flour addition decreased fat and protein contents and lightness (L) and increased hue angle (due to higher b), Instron compression values and cooking loss. Cured flavor intensity decreased and off-flavor intensity increased with the addition of WMG flour to frankfurters.