Study of the lactic acid bacteria throughout the manufacture of dry-cured lacón (a Spanish traditional meat product). Effect of some additives

Evaluation of the Quality Changes in Three Commercial Pastourma Samples during Refrigerated Storage Using Physicochemical, Microbiological, and Image Analyses Combined with Chemometrics

Despite the inherent stability of dried and cured products, such as pastourma, appropriate refrigeration remains essential for preserving their optimal characteristics. This study explored quality and safety characteristics in lamb, beef, and buffalo pastourma during 16-day refrigeration storage after package opening. The comprehensive approach employed Attenuated Total Reflection-Fourier-Transform Infrared (ATR-FTIR) spectroscopy, colorimetry, and image analysis, alongside physicochemical and microbiological analyses, to shed light on these alterations. The findings reveal a reduction in textural uniformity and color vibrancy (fading reds and yellows) across all samples during storage, with lamb pastourma exhibiting the most pronounced effects. Notably, image analysis emerged as a powerful tool, enabling the accurate classification of samples based on storage duration. Additionally, significant variations were observed in moisture content, hue angle, firmness, and TBARS levels, highlighting their influence on pastourma quality. The study documented a gradual decrease in lactic acid bacteria and aerobic plate count populations over time. ATR-FTIR spectra's interpretation revealed the presence of lipids, proteins, carbohydrates, and water. Protein secondary structures, demonstrably influenced by the meat type used, exhibited significant changes during storage, potentially impacting the functional and textural properties of pastourma. Overall, the findings contribute to a deeper understanding of pastourma spoilage during storage, paving the way for the development of improved preservation and storage strategies.

Heat-Treated Paraprobiotic Latilactobacillus sakei KU15041 and Latilactobacillus curvatus KU15003 Show an Antioxidant and Immunostimulatory Effect

The lactic acid bacteria, including Latilactobacillus sakei and Latilactobacillus curvatus, have been widely studied for their preventive and therapeutic effects. In this study, the underlying mechanism of action for the antioxidant and immunostimulatory effects of two strains of heat-treated paraprobiotics was examined. Heat-treated L. sakei KU15041 and L. curvatus KU15003 showed higher radical scavenging activity in both the 2-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and 2,2-diphenyl-1-picryl-hydrazyl (DPPH) assays than the commercial probiotic strain LGG. In addition, treatment with these two strains exhibited immunostimulatory effects in RAW 264.7 macrophages, with L. curvatus KU15003 showing a slightly higher effect. Additionally, they promoted phagocytosis and NO production in RAW 264.7 cells without any cytotoxicity. Moreover, the expression of tumor necrosis factor-α, interleukin (IL)-1β, and IL-6 was upregulated. These strains resulted in an increased expression of inducible nitric oxide synthase and cyclooxygenase-2. Moreover, the nuclear factor-κB and mitogen-activated protein kinase signaling pathways were stimulated by these strains. These findings suggest the potential of using L. sakei KU15041 and L. curvatus KU15003 in food or by themselves as probiotics with antioxidant and immune-enhancing properties.

Recent developments in off-odor formation mechanism and the potential regulation by starter cultures in dry-cured ham

Foul-smelling odors are main quality defects of dry-cured ham, which are connected with the excessive degradation of the structural proteins and excessive oxidation of lipids caused by the abnormal growth of spoilage microorganisms, threatening the development of dry-cured ham industry. Characterizing the key microorganisms and metabolites resulted in the spoilage of dry-cured ham, and discussing the relationship between spoilage microorganisms and metabolites are the key aspects to deeply understand the formation mechanism of off-odor in dry-cured ham. Until now, there is no detailed discussion or critical review on the role of spoilage microorganisms in developing the off-odor of dry-cured ham, and the regulation of off-odor and spoilage microorganisms by starter cultures has been not discussed. This review shows the recent achievement in the off-odor formation mechanism of dry-cured ham, and outlines the potential regulation of off-odor defects in dry-cured ham by starter cultures. Results from current research show that the abnormal growth of Lactic acid bacteria, Micrococcaceae, Enterobacteriaceae, Yeasts and Molds plays a key role in developing the off-odor defects of dry-cured ham, while the key spoilage microorganisms of different type hams are discrepant. High profile of aldehydes, acids, sulfur compounds and biogenic amines are responsible for off-odor development in spoiled dry-cured ham. Several starter cultures derived from these species of Staphylococcus, Penicillium, Debaryomyces, Pediococcus and Lactobacillus show a great potential to prevent microbiological hazards and improve flavor quality of dry-cured ham, whereas, the ecology, function and compatibility of these starter cultures with the processing parameters of dry-cured ham need to be further evaluated in the future.

Application of Fat-Tailed Sheep Tail and Backfat to Develop Novel Warthog Cabanossi with Distinct Sensory Attributes

This study compared the use of pork backfat (PF) and fat-tailed sheep tail and backfat (SF) on the physicochemical, fatty acids and sensory attributes of warthog cabanossi. There were no differences between weight loss during drying, moisture content, pH, water activity, salt content and lipid oxidation between the cabanossi types. However, protein and ash contents were higher in PF cabanossi whilst fat content was higher in SF cabanossi. The PF cabanossi had higher polyunsaturated fatty acids (especially n-6), lower monounsaturated fatty acids whilst the saturated fatty acid content was similar between the two cabanossi products. The n-3:n-6 ratio was more beneficial in the SF cabanossi. The descriptive sensory analysis showed two distinct products where PF cabanossi scored higher for most attributes. Although SF cabanossi scored less for these attributes, this cabanossi had unique and acceptable sensory attributes. This study concluded that fat-tailed sheep tail and backfat could be used to produce a unique cabanossi product of acceptable quality.

Low-sodium dry-cured rabbit leg: A novel meat product with healthier properties

Dry-cured rabbit legs were produced with a 50% reduction or replacement of NaCl by KCl and with the addition of monosodium glutamate (MG). The effect of this reformulation on technological, nutritional, and sensory characteristics was evaluated. The sodium reformulation did not show a great impact on Aw, pH, weight loss, and volatile profile of the samples. The samples presented high protein (31.5 to 36.1%) and low fat contents (3.2 to 5.7%). In addition, all essential amino acids presented an amino acid score greater than 1.0. The reformulated samples showed a sodium reduction of 46.2% while the addition of KCl to the formulations provided a healthy Na/K ratio. Oleic acid was the major fatty acid (FA) (31.3% of total FA) and healthy lipid indexes were observed for all samples. Finally, the addition of MG was effective to compensate for the sensory defects caused by sodium reformulation.

Isolation and Screening of Staphylococcus Xylosus P2 from Chinese Bacon: A Novel Starter Culture in Fermented Meat Products

A novel coagulase negative staphylococci strain as flavor agent for the processing of fermented meat products, Staphylococcus xylosus P2, was screened from Chinese bacon. It was identified on the basis of morphology and 16S rDNA sequence analysis. Its proteolytic, lipolytic and nitrate reductive activities were evaluated. And its growth ability at different temperatures, pH, sodium chloride, sodium nitrite concentrations, biogenic amine and pigment were investigated or detected. Furthermore, the fermentation evaluation with S. xylosus P2 as starter culture was carried out. The result showed that the fermented beef jerky was more attractive on the color, odor, texture, tasty and overall acceptability. It indicated that S. xylosus P2 would be a good starter culture for fermented meat products (jerky).

Physicochemical and sensory properties of dry-cured ham with dietary processed-sulfur supplementation

The aim of the present study was to explore the changes in physicochemical and sensory properties of dry-cured ham (from pigs that received a dietary supplement of processed sulfur, PS), as a function of the level of dietary PS. The following three groups were tested: (1) commercial basal feed (control, CON); (2) 0.1% of PS in the control diet (T1); and (3) 0.3% of PS in the control diet (T2). Dry-cured ham from T2 pigs had a higher moisture content and lower fat concentration than did that from the control pigs. Dry-cured ham T1 and T2 samples showed excellent lipid oxidation stability during storage and showed positive aroma scores in comparison with CON samples. Nonetheless, the total microbial plate count of dry-cured ham T1 (or T2) samples was significantly lower than that of CON samples, and volatile basic nitrogen of T1 (or T2) samples was higher than that of CON samples (P < 0.05). Concentrations of total free amino acids and sulfur-containing amino acids of ham T1 or T2 samples were significantly (P < 0.05) higher than those of control samples. Concentrations of polyunsaturated fatty acids of ham T1 and T2 samples were significantly higher than that of CON samples, whereas concentration of saturated fatty acids of CON samples was significantly higher. Thus, dry-cured ham from pigs receiving 0.3% PS in the diet showed the lowest fat concentration, increased nutrient quality and extended shelf life.

Enhancement of physicochemical, microbiological and sensory properties of dry-cured loin by using processed sulfur-fed pigs

The present study showed that processed sulfur supplementation and processing condition affected changes in physicochemical, microbial and sensory properties of dry-cured loin. The pigs were divided into two groups at the fattening phase: non-sulfur-fed pigs (NSFP) and 0.3% processed sulfur-fed pigs (SFP) in fattening phase. The crude fat content of SFP was lower than that of NSFP in raw meat and dry-cured loin. Lipid and pigment oxidation were suppressed in SFP compared with NSFP during whole process. Lightness of SFP was significantly higher than that of NSFP during storage. SFP showed higher colour stability than did NSFP during storage. Moreover, microbial spoilage of dry-cured loin was greatly prevented in SFP compared with NSFP. Free amino acids related to taste in SFP were significantly higher than those in NSFP. Polyunsaturated fatty acid of dry-cured loin from SFP group was higher than that of NSFP, while saturated fatty acid of NSFP was significantly higher than that of SFP. SFP had higher preference and flavour scores than did NSFP in a sensory test. Feeding processed sulfur improved the meat-quality characteristics and extended the shelf-life of meat products.