Effect of Modified Atmosphere Packaging Varying in CO2 and N2 Composition on Quality Characteristics of Dry Fermented Sausage during Refrigeration Storage.

The current study investigated the effects of the most suitable modified atmosphere packaging (MAP) on the physicochemical, microbiological, and sensory properties of fermented dry sausages during 45 days of refrigeration (4°C) storage period. Treatments were vacuum-packed (control), 25% CO2/75% N2 (MAP1), 50% CO2/50% N2 (MAP2), 70% CO2/30% N2 (MAP3), and 100% CO2 (MAP4). All MAP samples regardless of their CO2 composition significantly (p<0.05) decreased in pH, aw, total plate count, and lactic acid bacteria count values as compared to the vacuum-package during storage. The Enterobacteriaceae count in all MAP packaging was significantly (p<0.05) lower than the vacuum-packed samples and counts in MAP3 and MAP4 samples were markedly (p<0.05) lower than all other treatments in prolonged storage of 15 and 45 days. Based on the thiobarbituric acid reactive substance content at day 15 and 30 storage time, treatments are ranked as follows: Vacuum-packed>MAP1>MAP2>MAP3>MAP4. The a* of MAP4 was higher than all other treatments. In the final storage days, no variation was exhibited (p>0.05) among treatments in lactic acid aroma and sourness, and MAP2 samples had the lowest (p<0.05) overall acceptability. The use of MAPs with an increase in the CO2 from MAP1 to MAP4 samples can help in better microbial inhibition than vacuum package, and 70% CO2/30% N2 (MAP3) and 100% CO2 (MAP4) were effective to maintain several quality parameters (aw, pH, microbial inhibition, stability against lipid oxidation, and instrumental color traits) and extend the shelf life of dry fermented sausage.

Exploration of the Antioxidant Chemical Constituents and Antioxidant Performance of Various Solvent Extracts of Eighteen Plants.

This study examined the antioxidant chemical constituents (total phenolic and total flavonoid contents) and antioxidant activities [1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging, and ferric reducing antioxidant power (FRAP)] of different solvent extracts of eighteen functional plants. The active components of the target plants were extracted using four different solvents (methanol, ethanol, chloroform, and water). Mentha piperascens leaf exhibited a higher total phenolic content (chloroform and water extracts), total flavonoid content (all solvent extracts), DPPH radical scavenging activity (methanol, ethanol, and water extracts), ABTS radical scavenging activity (water extract), and FRAP radical scavenging activity (water extract) (in all solvent extracts). Similarly, Petasites japonicas root was another excellent and competent extract with a high total flavonoid content (in all four solvent extracts), DPPH and ABTS radical scavenging activity (methanol, ethanol, and water extracts), and FRAP activity (methanol, ethanol, and water extracts) (in all solvent extracts). Rubus coreanus fruit had the highest total phenolic content (methanol, ethanol, and water extracts), DPPH and ABTS radical scavenging activate (in all solvent extracts), and FRAP in its water extract were the two most effective functional plants. Based on the abundance of antioxidant chemical constituents and the most potent antioxidant activity demonstrated in this study, extracts from M. piperascens leaf, P. japonicas root, and R. coreanus fruit appear to be promising candidates to meet the current demand for natural preservatives in food and pharmaceutical industries.

Effect of Various Doses of Electron Beam Irradiation Treatment on the Quality Characteristics of Vacuum-Packed Dry Fermented Sausage during Refrigerated Storage.

In this study, we investigated the effect of electron beam irradiation on the physicochemical, microbiological, and sensory attributes of dry fermented sausage during 8 weeks of refrigerated storage at 4°C. The five doses of e-beam irradiation applied were: 0 kGy (control) and 1, 2, 3, and 4 kGy. All the experimental treatments led to a significant decrease in pH values during the storage period of 60 days (P<0.05). The 2-kGy treatment caused a significant (P<0.05) decrease in pH value, bacterial growth (total plate count, Listeria monocytogenes, Salmonella Typhimurium, and Escherichia coli), and thiobarbituric acid-reactive substances values than other irradiated fermented sausage batches during the study. Irradiation did not affect the water activity value of the fermented sausage samples. For color characteristics, 3 kGy exhibited significantly lower (P<0.05) L* (lightness) values than other irradiation treatments. A similar trend of significantly lower (P<0.05) a* (redness) and b* (yellowness) values was observed in all irradiated treatments than in the control. All the treatments showed no significant differences (P>0.05) in scores in sensory attributes (color and sourness); however, fermented sausage irradiated with 3 kGy had the highest sensory characteristics (overall acceptability) at the end of the storage period. In conclusion, 1, 2, and 3 kGy irradiation treatments can be beneficial for inhibiting lipid oxidation, controlling microbial growth, and maintaining sensory attributes of fermented sausage during storage, thereby enhancing their food safety and shelf stability.

Incorporation of Selected Strains of Pediococcus spp. on Quality Characteristics of Dry Fermented Sausage during Fermentation and Ripening.

This research investigated the physio-chemical and microbial quality characteristics of dry fermented sausage from selected Pediococcus strains: P. acidiliactici (PE1) and P. pentosaceus (PE2) as compared to commercial starter culture (COS) during fermentation and ripening. Treatments showed no substantial variation (p<0.05) in water activity (aw) values across the study period. PE1 and PE2 treatments exhibited similar (p>0.05) pH values and presented remarkable (p<0.05) lower volatile basic nitrogen (VBN) and thiobarbituric acid reactive (TBARS) content than COS treatment throughout the ripening period. However, the pH values in COS batch were considerably lower than others. PE1 samples presented a significant highest (p<0.05) counts both in lactic acid bacteria (LAB) and total plate count (TPC) than COS and PE2 treatments at 7 days fermentation, and it resulted in a similar and higher TPC count as COS after the ripening period. After the ripening process, treatments are ordered based on LAB counts as follows: COS>PE1>PE2. All batches presented similar redness and yellowness attributes since the 7 days of fermentation and in lightness across the study period. Treatments were similar (p>0.05) in springiness and chewiness traits across the study period and in hardness characteristics in the ripened products. Cohesiveness was higher in PE1 and COS batches. No variation (p>0.05) in aroma and sourness sensory attributes of treatments. The color attribute was highest (p<0.05) in PE1 and PE2 treatments and PE1 had the highest overall acceptability. The overall outstanding merit exhibited by PE1 can be utilized in the commercial production of high-quality dry fermented sausage.

Inoculation of Lactobacillus sakei on Quality Traits of Dry Fermented Sausages.

In this study, fermented sausage prepared by inoculating different strains of Lactobacillus sakei was assessed for their physiochemical, microbiological, and textural characteristics during fermentation and ripening. Five treatments were prepared: Control (commercial starter culture, C), L. sakei Korean Collection for Type Cultures (KCTC)-3802 (S1), L. sakei KCTC-3598 (S2), L. sakei KCTC-5053 (S3), and L. sakei KCTC-3603 (S4). The different strains of L. sakei did not show substantial differences (P>0.05) in pH values for dry fermented sausages at the end of the ripening period. Water activity (aw) values for all treatments were below 0.85 (P<0.05). Total viable count at the end of the study decreased in all L. sakei starter culture inoculated fermented sausages as S3> S2> S1> S4. High values of lactic acid bacteria (LAB) count and hardness were observed in the S2 batch as compared to other L. sakei inoculated treatments at the end of ripening (21st day). S3 inoculated with L. sakei strain exhibited significantly (P<0.05) higher value of a* (redness). A significant difference (P<0.05) in thiobarbituric acid reactive substances was exhibited in the following order: S4> S2> S1> S3> C. This study suggests that inoculation of S3 (L. sakei KCTC-5053) strain can improve the red color and reduce lipid oxidation while S2 enhances better microbiological quality as LAB. Incorporation of S3 and S2 strains accordingly can be helpful to enhance the quality of dry fermented sausages.

Ethanolic Extract of Moringa stenopetala Leaves Enhances the Quality Characteristics and Shelf-Life of Vacuum-Packed Pork Patty during Refrigeration Storage.

Studies reported that the moringa plant provides various bioactive compounds. The present study investigated the effect of an ethanolic extract of Moringa stenopetala leaves (MLE) on the storage consistency of vacuum-packed pork patty during refrigeration storage (4°C). Four treatments prepared were: control (without any preservative) and patties blended with 0.1% MLE (MLE1), 0.05% MLE (MLE2), and 0.2% potassium sorbate (PS). Patties incorporated with 0.05 and 0.1% MLE scored significantly lower (P<0.05) pH values compared with the control at the final storage time and thiobarbituric acid reactive values as compared to both the control and PS treated patties throughout the study period. Moreover, patties added with MLE had a significantly lower (P<0.05) total plate count than the control and the count decreased concomitantly with an increase in MLE concentration. The addition of MLE (0.1 and 0.05%) presented significantly higher (P<0.05) redness (a*) values than the control across storage time. Sensory attributes of samples did not vary significantly (P>0.05), and all treatments had similar overall acceptability scores during storage. In conclusion, incorporation of 0.1% and 0.05% MLE suppressed microbial growth and delayed the onset of oxidative rancidity in pork patties during storage without any effect on the sensorial properties and overall acceptability. As an organic preservative, MLE can help in extending the shelf life of pork patties to satisfy the demands of modern consumers for organic, healthy, and safe food ingredients.