• Food Science and Biotechnology
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• v.18 no.4
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• pp.985-990
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• 2009

Response surface methodology (RSM) was applied to determine the optimum drying conditions for pork jerky. The physicochemical properties of pork jerky, such as final moisture content, water activity (Aw), pH, and shear force were investigated. In addition, sensory characteristics of pork jerky were evaluated and were used as a parameter for determining the optimum condition. Pork jerky samples were dried at different temperatures between 40 to $80^{\circ}C$ for the time ranged from 0 to 10 hr. The predicted values for moisture content, Aw, and shear force of dried pork samples were in good agreement with the experimental values with correlation coefficients ($R^2$) of 0.95, 0.96, and 0.97, respectively. Both drying temperature and time significantly (p<0.01) affected moisture content, Aw, pH, and shear force and their interactions were also significant at p<0.01 except for Aw. RSM showed the optimum drying conditions for pork jerky, based on moisture content, shear force, and sensory evaluation to be oC$65-70^{\circ}C$ for 7-8 hr.

• Food Science of Animal Resources
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• v.36 no.5
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• pp.626-634
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• 2016

This study was conducted to compare the physicochemical, microbiological and antioxidant activities of sun-dried venison amended with green tea powder (T1-3: 0, 0.5, and 1%) and Hanwoo beef jerky. Sliced beef and venison shank were marinated and sun-dried at 28-30℃ and 30-35% RH for 3.5 h. The venison jerky had a higher ash and protein content, and lower moisture and fat content than the control (p<0.05). T3 (venison+green tea powder 1%) showed a lower a_w than all other samples during storage for 10 and 20 d (p<0.05). Hunter’s color a* and b* values of T2 and T3 were lower than those of T1 and the control at day 0 (p<0.05). Saturated fatty acid was significantly higher in T1, while PUFA was higher in T2 and T3 (p<0.05). Overall sensory scores of venison jerky were lower than those of the control, except for T2, which had a similar color, flavor, saltiness and acceptability as the control. T2 and T3 showed a significant decrease in TPCs after storage for 20 d (p<0.05). The TBARS values of T3 jerky were lower than those of other jerky samples (p<0.05).

• Food Science of Animal Resources
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• v.28 no.5
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• pp.675-680
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• 2008

The physical quality and microbial safety of Korean beef jerky was evaluated at various steps during its preparation. Microbial counts in raw beef demonstrated mesophillic bacteria at 4.20 Log CFU/g, psychrotrophic bacteria at 3.85 Log CFU/g, anaerobic bacteria at 4.90 Log CFU/g, and yeast and molds at 1.92 Log CFU/g. Spore-forming bacteria and coliforms were not detected in raw beef samples. Spices and spiced meats showed similar trends in microbial counts, demonstrating minimal microbial contamination during these stages of preparation. The final beef jerky product exhibited counts of mesophillic bacteria at 1.15-1.66 Log CFU/g, psychrotrophic bacteria at 1.15-1.66 Log CFU/g, and anaerobic bacteria at 0.81-1.72 Log CFU/g. Spore-forming bacteria, yeast and molds, and coliforms were not detected in beef jerky. Significant differences from added ingredients occurred for instron textural profile analysis traits for hardness. In general, Korean beef jerky with humectant and tenderizer had lower hardness than control (without humectant and tenderizer). Also, the sample added with 0.01% protease from Streptomyces griseus had lower hardness than all samples. All samples had 0.7l to 0.72 water activities, and the color and pH were not shown in significant changes of all samples.

• Food Science of Animal Resources
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• v.30 no.6
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• pp.930-937
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• 2010

This study was carried out to investigate the textural and sensory properties of pork jerky with differently added sources of tenderizer or humectant at final concentrations of 2 or 5% (v/w). Pork jerky treated with 5% glycerol, kiwi, or pineapple had lower moisture content and water activity than that of control pork jerky (p<0.05). The addition of tenderizer or humectant resulted in a lower shear force than that of control (p<0.05). The addition of 2 or 5% glycerol resulted in higher equilibrium moisture content (EMC) than other treatments, and addition of tenderizer or humectant produced a higher EMC than that of control (p<0.05). Furthermore, addition of pineapple and kiwi to the samples affected the structures of the myosin heavy chain and the actin filaments of myofibrillar protein, respectively. Trained panel sensory evaluations indicated that pineapple enhanced the flavor score, whereas tenderness score was improved by the addition of tenderizer or humectant (p<0.05).

• Korean journal of food and cookery science
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• v.23 no.5
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• pp.579-588
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• 2007

The effects of packaging methods on the quality of beef and pork jerky samples prepared Korean- style were investigated in terms of their pH, water activities ($A_w$), thiobarbituric acid (TBA) values, total bacterial counts, and sensory evaluations during storage at room temperature ($25^{\circ}C$ for 90 days. The jerky was subjected to plastic packaging and vacuum packaging conditions at $25^{\circ}C$ Levels of pH slightly decreased during storage (p<0.05), but there was no significant difference between the packaging methods. (p>0.05) Also, water activity decreased as storage time passed (p<0.05), and vacuum packaging resulted in a higher water activity value than plastic packaging. The hardness value of the jerky in plastic packaging was higher than that in vacuum packaging (p<0.05). In addition, hardness and TBA increased over the storage periods (p<0.05). The total bacterial counts in of the vacuum packaged jerky were lower than those of the plastic packaged jerky. The vacuum packaging treatments had higher scores than the plastic packaging treatments for all sensory traits. Based on our findings, we conclude that vacuum packaging is a more effective storage method than plastic packaging for jerky.

• Food Science of Animal Resources
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• v.32 no.6
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• pp.732-739
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• 2012

The aim of this study was to investigate the effect of chicken feet gelatin and wheat fiber levels on the quality characteristics properties of semi-dried chicken jerky. The obtained chicken feet gelatin swollen with hydrochloric solution (0.1 N HCl, pH $1.31{\pm}0.02$) was dehydrated via freeze-drying. Six formulations of chicken jerky that were prepared, based on the ratio of chicken meat, chicken feet gelatin and wheat fiber, were 100:0:0, 98:0:2, 99:1:0, 97:1:2, 98:2:0 and 96:2:2, respectively. The moisture content of semi-dried chicken jerky containing 2% wheat fiber was higher than that of jerky without the added fiber (p<0.05); moreover, an increase in the content of chicken feet gelatin also increased the moisture content. The drying yield of the samples increased with an increase in chicken feet gelatin. In addition, the drying yield of samples containing 2% wheat fiber was higher (p<0.05) than those without the added wheat fiber. However, the shear force of the samples significantly decreased with the increase in chicken feet gelatin content. Further, the shear force of the samples containing 2% wheat fiber was higher (p<0.05) than those without the added wheat fiber. No significant differences, except for color, were observed in the sensory analysis among the treatments.

• Food Science of Animal Resources
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• v.33 no.2
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• pp.181-188
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• 2013

The aim of this study was to investigate the quality properties of beef jerky replaced salt with soy sauce, red pepper paste, and soybean paste. The quality properties of beef jerky including final water activity ($a_w$), moisture content, pH, color, shear force, total plate counts, thiobarbituric acid reactive substance (TBARS) values, and sensory evaluations were investigated. The sliced beef samples were marinated in salt (control), soy sauce (T1), red pepper paste (T2), and soybean paste (T3) for 24 h and then dried at $70^{\circ}C$ for 6-8 h. The water activity of finished beef jerky varied from 0.72 to 0.70. The water activity for control and T1 samples decreased more rapidly as drying proceeded up to 6 h. The samples with salt replacement showed a lower pH and lightness than the control (p<0.05). The T1 sample showed a significant decrease in total plate counts after 21 d of storage (p<0.05). The TBARS for all treatments increased with storage days (p<0.05). The TBARS were significantly lower in T2 and T3 samples compared to control and T1 until 21 d of storage (p<0.05). The samples with salt replacement showed a lower intensity of saltiness than the control. Sensory evaluations found that the replaced soy sauce of beef jerky samples had better overall acceptability scores than the other treatment samples. It was concluded that replacing salt with soy sauce can delay lipid oxidation and enhance the sensory acceptance of beef jerkies.

• Food Science of Animal Resources
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• v.44 no.2
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• pp.464-482
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• 2024

This study aimed to determine the effects of humectants on moisture content, water activity, tenderness, color, microbiological analysis, protein denaturation, and oxidation of jerky. A thorough search for papers published in scientific journals that examined the impacts of humectants on jerky was carried out using Web of Science, Google Scholar, PubMed, and Science Direct. Only 14 studies matched inclusion requirements. They were used in the meta-analysis to synthesise quantitative findings. In the current investigation, jerky produced with beef, poultry, goat, or pork was used. The standardised mean difference (SMD) between treatments with humectants and controls was examined to investigate the effects of humectants using random-effects models. Heterogeneity was investigated using meta-regression. A subgroup analysis was carried out for significant factors. Results revealed that the addition of humectants had no significant impact on water activity, pH, fat, ash, CIE L^*, or CIE a^* (p>0.05). However, humectant addition significantly increased moisture (SMD=1.28, p<0.05), CIE b^* (SMD=1.67, p<0.05), and overall acceptability (SMD=1.73, p<0.05). It significantly decreased metmyoglobin (SMD=-0.96, p<0.05), shear force (SMD=-0.84, p<0.05), and protein (SMD=-1.61, p<0.05). However, it was difficult to get a firm conclusion about how humectants affected the myofibrillar fragmentation index, total plate count, and 2-thiobarbituric acid-reactive substances because there were fewer than ten studies. To sum up, the proper use of humectants in jerky demands careful attention to both type and quantity, needing a delicate balancing act with other contributing factors.

• Food Science and Preservation
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• v.16 no.6
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• pp.875-883
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• 2009

We investigated the effects of manufacturing method on the quality of beef jerky using electron micrography. Six types of beef jerky were prepared by the addition of sugar (A), licorice (B), one of three kinds of spice extract (clove: C, fennel fruit: D, and Chungyang green pepper extract: E), or a mixture of all spice extracts (F). Microstructural changes in beef jerky during preparation by drying, with respect to drying method and the nature of the added spice extract, were observed by scanning electron micrography (SEM) and transmission electron micrography (TEM). The latter technique showed that the microstructure of fresh meat showed actin and myosin in myofibril lines, and also mitochondria and inner membranes. Beef muscle structure was broken at many myofibril lines and decomposition of inner membrane material was evident after seasoning. SEM of air-blast dried beef jerky with added medicinal herb extracts showed both large spaces and regular myofibrils, whereas hot air-dried beef jerky had no spaces and the muscle myofibrils were still evident. After review of all available micrographs from SEM and TEM, we concluded that use of medicinal herb extracts could be helpful in preserving the muscle myofibril structure during drying, and the air-blast drying method is recommended to optimize the textural quality characteristics of beef jerky.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.1
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• pp.81-86
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• 2007

This study was conducted to evaluate the quality characteristics of pork jerky added with the extracts of paprika (Capsicum annuum L.) and Japanese apricot (Prunus mume Sieb. et Zucc.). Color stability, lipid oxidation, texture, and consumer acceptability of the pork jerky were also compared before and after storage of 70 days. The pork jerky added with 0.5% paprika extract and 3.5% Japanese apricot extract had the highest score for overall acceptability. The redness (a-value) of the pork jerky added with the natural extracts had a similar level as the one with nitrite. The extracts of paprika and Japanese apricot were also effective in inhibiting the lipid oxidation of the pork jerky during storage. In texture measurement, the total shear force of the natural extracts-treated sample was lower than that of control (the natural extracts-untreated samples). All sensory properties of the pork jerky were significantly (p<0.05) improved by the addition of the natural extracts. The results of this study indicated that the extracts of paprika and Japanese apricot could be used as natural agents for retarding color and lipid oxidations.