Fermented Meat Products Research Articles

Indigenous Lactic Acid Bacteria as Antioxidant Agents in the Production of Organic Raw Fermented Sausages

The study aimed to assess the impact of lactic acid bacteria (LAB) strains on the antioxidant, physico-chemical properties, and microbiological quality of fermented sausages. Five treatments of raw sausages were prepared: two controls without LAB addition (C, P), and three samples with LAB addition (SCH1, BAL6, KL14). Fatty acid composition, cholesterol content, physico-chemical, microbiological tests, and antioxidant assays, were performed at time 0 and after 1 and 2 months of storage. A significantly higher ability to scavenge free radicals of DPPH (2,2-diphenyl-1-picrylhydrazyl) was found in sausages with all LAB strains. In the case of the ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) test, it was noted that KL14 treatment had higher antioxidant activity. The main fatty acids in sausages were monounsaturated and saturated. A significantly lower cholesterol content was observed in sausages with the addition of LAB. Sausages with LAB strains differed significantly in pH value. Water activity decreased significantly during storage. After 2 months of storage, the sausages with BAL6 and KL14 strains were characterized by significantly lower redox potential and a lower TBARS (thiobarbituric acid reactive substances) index. It was found that P sausages had the darkest color. SCH1, BAL6, and KL14 strains were also capable of producing red color. The total number of microorganisms in the sausages was high, which is mainly due to the high LAB content and yeast and mold counts. No spoilage or pathogenic microflora were detected. Indigenous LAB strains have the potential to improve the quality and safety of fermented meat products.

Improvement of the safety of artisanal Spanish fermented sausages: Spotlight on the role of bacteriocinogenic Lactiplantibacillus paraplantarum against a Companilactobacillus alimentarius histaminogenic strain

Biogenic amines (BA) in fermented sausages result from amino acid decarboxylation by microbial activity, either from technological or spoilage bacteria. Certain lactic acid bacteria typically found in fermented sausages are characterised for their ability to produce BA, especially histamine and tyramine. On the other hand, the bacteriocinogenic strain Lactiplantibacillus paraplantarum BPF2, isolated from a Spanish spontaneously dry-fermented sausages, has been characterized by good technological properties, production of leucocin K with antimicrobial activity against Listeria monocytogenes and ability to reduce the accumulation of BA in the final products. The antagonistic activity of leucocin K bacteriocin was tested in vitro against Companilactobacillus alimentarius SE14 (histamine producer), Enterococcus faecalis EF37 (tyramine producer), and L. monocytogenes Scott A. The inhibition of Comp. alimentarius SE14 by Lpl. paraplantarum BPF2 was assessed in traditional Spanish fermented sausages obtained in pilot plant, and chemico-physical parameters, microbial counts, and BA accumulation were monitored during fermentation and ripening. Leucocin K produced by Lpl. paraplantarum BPF2 was active in vitro against Comp. alimentarius SE14 and L. monocytogenes but was ineffective against E. faecalis EF37. The inoculation of the strain BPF2 as starter culture did not affect the expected chemico-physical (pH and colour) and microbial characteristics of the dry-fermented sausages. On the other hand, this strain was effective to significantly reduce the accumulation of histamine produced by the strain SE14, as well as putrescine and cadaverine. These findings demonstrated the relevant role of bacteriocin-producing strains as bio-protective starter cultures in improving the safety and quality of fermented meat products.

Screening and application of functional autochthonous starter culture from cured meat, which can reduce nitrite content.

Cured meat is a fermented meat product from the traditional Chinese culture made by natural fermentation. In this study, five bacteria strains were screened from cured meat using 16S rDNA technology, and a functional local starter was selected, which was applied to the production of cured meat to standardize the production of cured meat and improve the quality of cured meat. By studying the fermentation characteristics of strain these strains, this study found that the fermentation characteristics of L. mesenteroides and S. lactis are ideal. L. mesenteroides and S. lactis were used as starter cultures in fermented bacon. Then, this study compared the quality of fermented beef with Sichuan bacon, Hunan bacon, and Xinyang bacon. The results suggested that L. mesenteroides and S. lactis can improve the sensory and texture properties of the products and reduce the moisture content, water activity, pH value, and protein content of fermented beef products. More importantly, L. mesenteroides can significantly reduce the nitrite content (25.34%) and nitrosamine content (29.69%) in fermented beef, which provides an excellent guarantee for the safety of cured meat. In this study, a functional fermentation strain-L. mesenteroides could degrade the nitrite content of fermented meat products and improve their sensory and textural properties-was screened to provide some reference value for the later development of functional strains suitable for fermented meat products.

The regulation of volatile flavor compounds in fermented meat products mediated by microorganisms: A review

Fermented meat products are widely consumed and favored by consumers because of their unique flavor and texture. Flavor formation is a complicated biochemical process, and microorganisms (mainly lactic acid bacteria, staphylococci, yeasts, and molds) play an essential role in flavor regulation. Elucidating the role of microorganisms in regulating the flavor formation of fermented meat products is critical for rationally designing microorganisms to improve the flavor quality of fermented meat products. Therefore, microorganisms, volatile compounds, and flavor-generating mechanisms of microorganisms in fermented meat products are summarized. This review also highlight correlations between microorganisms and flavor development and the effects of microorganisms on flavor development, which may provide important progress for the selection and application of microorganisms to improve the flavor of fermented meat products.

Insights into the molecular mechanisms of lipid metabolism of air-dried goose on the formation of flavor substances by co-inoculation of lactic acid bacteria and staphylococcus based on GC-MS and lipidomics

Microorganisms and lipids always interact in a complex way in the meat matrix, which affects the flavor of meat products. This study aimed to examine the impact of complex fermentation with distinct microorganisms on fat oxidation, lipid profile, and the biochemical pathways involved in flavor substance formation. GC–MS analysis revealed that 12 key volatile substances including hexanal, heptanal, benzeneacetaldehyde, decanal, 1-nonanol, 1-hexanol, 1-octen-3-ol were responsible for the flavor variations in geese. Lipidomics analysis of three groups identified 440 lipid molecules, with triglycerides and glycerophospholipids being the most abundant categories. Spearman correlation analysis showed that 4 key volatile substances exhibited positive correlations with lysophosphatidylethanolamines, lysophosphatidycholines, phosphatidylcholines, phosphatidylethanolamines. The data presented herein facilitate an understanding of the lipid dynamics during fermentation and provide insights into the potential for controlling the flavor quality of fermented air-dried meat products.

An effective means to improve the flavor quality of traditional fermented sour meat: The salt reduction strategy

The flavor formation of fermented meat products is significantly influenced by salt. In this study, the flavor analysis methods of electronic tongue and nose, gas chromatography-mass spectrometry, and liquid chromatography-mass spectrometry were utilized to explore the effect of salt content on the formation of sour meat flavor. The results demonstrated a significant decrease in pH value with the reduction of salt content (P < 0.05), while there was a significant rise in thiobarbituric acid reactive substances (TBARS) value associated with the decline in salt content (P < 0.05). Alcohols, aldehydes, and esters such as 1-octen-3-ol, 3-methyl-1-butanol, hexanal, heptanal, ethyl octanoate, ethyl heptanoate, etc. were considered to have significant contributions to the overall flavor of sour meat. The rapid accumulation of these aroma compounds under low-salt conditions was regarded as one of the key factors in the overall flavor enhancement of sour meat products. Additionally, the low-salt fermentation also promoted the accumulation of free amino acids and free fatty acids in sour meat products, thereby facilitating the formation of more complex aroma compounds. This study offers new technological ways to improve the conventional method of fermenting sour meat and offers theoretical justification for studies on salt reduction in conventionally fermented meat products.

Deciphering contaminants and toxins in fermented food for enhanced human health safeguarding.

Fermented foods have been a component of the human diet since ancient times, including live bacteria employed to restore gut health, contributing to the frontline of functional food progression. Human concern about the harmful consequences of possible contaminants has increased significantly as their toxicity, carcinogenicity, and teratogenicity have become more publicized. In order to take preventive measures, it is essential to correctly identify and define the implications of contaminants and toxins in human health and intestinal microbiota balance for preventing or diagnosing epidemics before they cause damage. The longer food chain that results from urbanization and underreporting of diseases makes it harder to correlate contaminated food to disease, which in turn presents challenges to improving food safety. This research aims to present the potential physical, chemical, and microbiological pollutants and toxins found in fermented products and their effects on human health. The scope tackles various categories of fermented foods, such as dairy products, alcoholic and nonalcoholic beverages, fermented meat products, traditional bakery products, and fermented cereals and vegetables. Furthermore, it examines specific control processes such as rigorous sanitation protocols, advanced packaging technologies, regulatory harmonization, and decontamination methodologies used to prevent the release of contaminants from fermented foods. Future viewpoints and opportunities are briefly mentioned in the conclusion.

Effects of salt and rice flour concentration on microbial diversity and the quality of sour meat, a Chinese traditional meat

This study investigated the effects of salt (3 % and 6 %, m/m) and rice flour (10 % and 20 %, m/m) addition in sour meat, a traditional Chinese fermented meat. It was found that salt has greater effect than rice flour addition in spontaneous fermentation. Low-salt groups had lower pH and higher titratable total acid. In the low-salt groups, the dominant genera were Lactobacillus and Lactococcus, whereas Staphylococcus, Weissella, and Tetragenococcus were dominant in the high-salt groups. Higher total free amino acids and essential amino acids, organic acids, hexanoic acid ethyl ester and octanoic acid ethyl ester were found in the low-salt groups. The RDA analysis revealed that Lactococcus was closely related to product quality, with the S3F10 (3 % salt and 10 % rice flour) group outperforming the others in the sensory evaluation. Therefore, 3 % salt and 10 % rice flour were considered more appropriate for the production of healthy and tasty fermented sour meats.

Combination of contact ultrasound and infrared radiation for improving the quality and flavor of air-dried beef during hot air drying

Air-dried beef, a traditional dry fermented meat product in China, whose quality is largely influenced by processing conditions. In this study, contact ultrasound (CU) and infrared radiation (IR) were employed to enhance hot air drying (HAD), with an investigation into the mechanisms underlying improvements in quality and flavor. Samples subjected to CU and IR treatments during HAD (CU-IRD) demonstrated superior color (L* = 42.68, a* = 5.05, b* = −3.86) and tenderness (140.59 N) than HAD group, primarily attributed to reduced drying times and alterations in ultrastructure. Analyses utilizing SDS-PAGE and total volatile basic nitrogen (TVB-N) revealed that HAD and CU-HAD resulted in significant protein oxidation (197.85 mg TVB-N/kg and 202.23 mg TVB-N/kg, respectively), while IR treatments were associated with increased thermal degradation of proteins, producing lower molecular weight peptides. Compared with HAD group, the activities of certain lipases and proteases were enhanced by ultrasound and infrared treatments, leading to the release of greater amounts of free fatty acids and flavor amino acids. Furthermore, the thermal effects of infrared and the cavitation effects of ultrasound contributed to increased fat oxidation, amino acid Strecker degradation, and esterification reactions, thereby augmenting the diversity and concentration of volatile flavor compounds, including alkanes, ketones, aldehydes, and esters. These findings indicate that the synergistic application of CU and IR represents a promising strategy for enhancing the quality of air-dried beef.

Substitution of Animal Fat and Sodium Nitrite with Hemp Seed Oil: Effect on the Nutritional Value, Sensory Characteristics, and Shelf Life of Fermented Salami.

Recently, products of plant origin have been utilized to extend the shelf life of meat products. This study examined the impact of hemp seed oil as a replacement for animal fat and sodium nitrite on the nutritional, physicochemical, technological, and sensory traits of fermented salamis. Five treatments were prepared: S0 (100 mg/kg NaNO2), S1 (2% hemp oil and 50 mg/kg NaNO2), S2 (4% hemp oil and 50 mg/kg NaNO2), S3 (2% hemp oil), and S4 (4% hemp oil). The addition of hemp seed oil did not affect proximate composition but improved fatty acid composition and lipid quality nutritional indices. Microbial growth was consistent across all treatments. Active acidity (pH) and water activity (aw) were influenced by hemp seed oil and/or sodium nitrite. Salamis containing only hemp seed oil exhibited lower redness and chroma values during storage. Hemp seed oil led to higher lipid peroxidation, mitigated by sodium nitrite. The addition of hemp seed oil and varying levels of sodium nitrite significantly impacted salami texture. Sensory evaluation showed consumer acceptance of hemp seed oil-enhanced salamis. In conclusion, hemp seed oil can be used as a functional ingredient to improve the nutritional value and healthiness of fermented meat products when combined with reduced sodium nitrite content.

Self-assembled dipeptide confined in covalent organic polymers for fluorescence sensing of tryptamine in fermented meat products.

Diphenylalanine(FF)-Zn self-assembly (FS) confined in covalent organic polymers (FS@COPs) with efficient fluorescence was synthesizedfor fluorescence sensing of biogenic amines, which was one of the most important indicators for monitoring food freshness. FS@COPs combined excellent biodegradability of self-assembled dipeptide with chemical stability, porosity and targeted site recognition of COPs. With an optimal excitation wavelength of 360 nm and an optimal emission wavelength of 450 nm, FS@COPs could be used as fluorescence probes to rapidly visualize and highly sensitive determination of tryptamine (Try) within 15 min, and the linear range was from 40 to 900 μg L-1 with a detection limit of 63.08 μg kg-1. Importantly, the FS@COPs showed a high fluorescence quantum yield of 11.28%, and good stability, solubility, and selectivity, which could successfully achieve the rapid, accurate and highly sensitive identification of Try. Furthermore, we revealed the mechanism of FS@COPs for fluorescence sensing of targets. The FS@COPs system was applied to the fluorescence sensing of Try in real samples and showed satisfactory accuracy of 93.02%-105.25%.

Correlation between the Characteristic Flavour and Microbial Community of Xuanwei Ham after Ripening

Xuanwei ham is a traditional fermented meat product in China with a unique production process and excellent-quality reputation at home and abroad. To reveal the microbial community succession of Xuanwei ham at different post-ripening times (W1-4) and its relationship with flavour formation, the microbial community, free amino acids, and volatile flavour compounds (VOCs) were analysed by high-throughput sequencing, liquid chromatography (LC), and gas chromatography–mass spectrometry (GC-MS), respectively. A total of 25 free amino acids were detected, among which W3 contained the fewest, and most were generally lower than in hams in the other three years. Fifty-nine VOCs were detected, among which 17 were esters, and the highest ester content was found in W4. Analysis of the bacterial community composition revealed that the bacterial community composition of ham samples from W3 and other years differed greatly, and at the gate level, the dominant bacterial group of Xuanwei ham from different years was Pseudomonadota. At the genus level, the most abundant genera in W1, W2, and W4 were all dominated by Sarocladium, Klebsiella, and Vibrio, with Klebsiella being the most abundant in W1. The most abundant genus in W3 was Vibrio, and the second most dominant genera were Sarocladium and Gammaretrovirus. In short, this study provides a theoretical basis for the storage, quality, and improvement of Xuanwei ham.

Fabrication of fluorescence probe based on molecularly imprinted polymers on red emissive biomass-derived carbon dots coupled with smartphone readout for tyramine determination in fermented meat products.

A fluorescence probe based on molecularly imprinted polymers on red emissive biomass-derived carbon dots (r-BCDs@MIPs) was developed to detect tyramine in fermented meat products. The red emissive biomass-derived carbon dots (r-BCDs) were synthesized by the one-step solvothermal method using discarded passion fruit shells as raw materials. The fluorescence emission peak of r-BCDs was at 670nm, and the relative quantum yield (QY) was about 2.44%. Molecularly imprinted sensing materials were prepared with r-BCDs as fluorescent centers for the detection of trace tyramine, which showed a good linear response in the concentration range of tyramine from 1 to 40µg L-1. The linear correlation coefficient was 0.9837, and the limit of detection was 0.77µg L-1. The method was successfully applied to the determination of tyramine in fermented meat products, and the recovery was 87.17-106.02%. The reliability of the results was verified through high-performance liquid chromatography (HPLC). Furthermore, we combined the r-BCDs@MIPs with smartphone-assisted signal readout to achieve real-time detection of tyramine in real samples. Considering its simplicity and convenience, the method could be used as a rapid and low-cost promising platform with broad application prospects for on-site detection of trace tyramine with smartphone-assisted signal readout.

Screening and evaluating yeast strains with antioxidant potential from the traditional dry sausage of northern China

The antioxidant yeast strains isolated from the traditional dry sausage of northern China were screened, and their antioxidant role in dry sausage was evaluated. The survival abilities of seven strains were relatively superior when exposed to 12 mM H2O2 after 48 h, and these were subsequently inoculated into dry sausage. Among them, Debaryomyces hansenii HRB1 and Rhodotorula mucilaginosa SH9 treatments yielded lower peroxide value (0.48 and 0.51 mmol/kg, respectively), thiobarbituric acid reactive substance value (0.51 and 0.50 mg MDA/kg, respectively), and carbonyl content (8.67 and 8.70 nmol/kg protein, respectively) values (P < 0.05), indicating the superior antioxidant activity of these two strains. Meanwhile, yeast inoculation reduced the alcohol content and increased the ester content in the dry sausage. In particular, the level of hexanal, a byproduct of lipid oxidation, was reduced. A sensory evaluation demonstrated that the inoculated dry sausage had the higher salty taste and the lower sour taste and rancid taste. Overall, D. hansenii HRB1 not only effectively inhibited lipid and protein oxidation and reduced the perception of oxidative taste, but also enhanced the aroma profile of dry sausage and improved overall sensory quality. This study offers a novel perspective for the development of antioxidant starters and enhancement of fermented meat product quality.

A smartphone-combined ratiometric fluorescence molecularly imprinted probe based on biomass-derived carbon dots for determination of tyramine in fermented meat products

A ratiometric fluorescence molecularly imprinted probe employing two distinct emission wavelengths of biomass carbon dots was developed for highly selective and visual quantitative detection of tyramine in fermented meat products. The red emission biomass carbon dots were employed as responsive elements, and the blue ones were utilized as the reference elements. The molecularly imprinted polymers were incorporated in the ratiometric sensing to distinguish and adsorb tyramine. With the linear range of 1–60 μg/L, the ratiometric fluorescence molecularly imprinted probe was successfully applied to detect tyramine in real samples with the satisfactory recoveries of 79.74–112.12% and the detect limitation of 1.3 μg/kg, indicating that this probe has great potential applications for the detection of tyramine in real samples. Moreover, smartphone-based fluorescence signal recognition analysis on hand has been developed for the quantitative analysis of tyramine, providing a portable visual optical analysis terminal for rapid on-site determination of tyramine.

Metagenomic profiles of the antimicrobial resistance in traditional Chinese fermented meat products: Core resistome and co-occurrence patterns

Antimicrobial resistance (AMR) poses a significant challenge to global health, and the presence of antibiotic resistance genes (ARGs) in food poses a potential threat to public health. Traditional Chinese fermented meat products (FMPs) are highly favored because of their unique flavors and cultural value. However, microbial safety and the potential distribution and composition of AMR in these products remain unclear. In this study, a comprehensive analysis of bacterial composition and antibiotic-resistant populations in 216 samples of traditional fermented meat products from different regions of China was conducted using a metagenomic approach. Staphylococcus was the most abundant genus in the samples, accounting for an average abundance of 29.9 %, followed by Tetragenococcus (17.1 %), and Latilactobacillus (3.6 %). A core resistome of FMP samples was constructed for the first time using co-occurrence network analysis, which revealed the distribution and interrelationships of ARGs and bio/metal-resistant genes (BMRGs). Random forest analysis identified the lincosamide nucleotidyltransferase lnuA and the multidrug and toxic compound extrusion (MATE) transporter abeM as potential indicators for assessing the overall abundance of the core resistome. Additionally, Staphylococcus, Acinetobacter, and Pseudomonas were identified as hosts constituting the core resistome. Despite their low abundance, the latter two still serve as major reservoirs of antibiotic resistance genes. Notably, Lactococcus cremoris was identified as the key host for tetracycline resistance genes in the samples, highlighting the need for enhanced resistance monitoring in lactic acid bacteria. Based on our findings, in the microbial safety assessment of fermented meat products, beyond common foodborne pathogens, attention should be focused on detecting and controlling coagulase-negative Staphylococcus, Acinetobacter, and Pseudomonas, and addressing bacterial resistance. The quantitative detection of lnuA and abeM could provide a convenient and rapid method for assessing the overall abundance of the core resistome. Our findings have important implications for the control of bacterial resistance and prevention of pathogenic bacteria in fermented meat products.

Shotgun metagenomic investigation of foodborne pathogens and antimicrobial resistance genes in artisanal fermented meat products from the Mediterranean area.

In this pilot study, we compared the metagenomic profiles of different types of artisanal fermented meat products collected in Italy, Greece, Portugal, and Morocco to investigate their taxonomic profile, also in relation to the presence of foodborne pathogens and antimicrobial resistance genes. In addition, technical replicates of the same biological sample were tested to estimate the reproducibility of shotgun metagenomics. The taxonomic analysis showed a high level of variability between different fermented meat products at both the phylum and genus levels. Staphylococcus aureus was identified with the highest abundance in Italian fermented meat; Escherichia coli in fermented meat from Morocco; Salmonella enterica in fermented meat from Greece; Klebsiella pneumoniae and Yersinia enterocolitica in fermented meat from Portugal. The fungi Aspergillus, Neosartoria, Emericella, Penicillum and Debaryomyces showed a negative correlation with Lactococcus, Enterococcus, Streptococcus, Leuconostoc and Lactobacillus. The resistome analysis indicated that genes conferring resistance to aminoglycoside, macrolide, and tetracycline were widely spread in all samples. Our results showed that the reproducibility between technical replicates tested by shotgun metagenomic was very high under the same conditions of analysis (either DNA extraction, library preparation, sequencing analysis, and bioinformatic analysis), considering both the degree of overlapping and the pairwise correlation.

Effects of exogenous autoinducer-2 precursor on the ability of Lactiplantibacillus plantarum SH7 to degrade biogenic amines: In vitro and in a dry-sausage model

The effects of the exogenous autoinducer-2 (AI-2) precursor, 4,5-dihydroxy-2,3-pentanedione (DPD; 0, 300, 600, and 900 nmol/L), on the degradation capacity of Lactiplantibacillus plantarum SH7 toward biogenic amines (BA) were investigated both in vitro and in a dry-sausage model. L. plantarum SH7 exhibited a significant increase in BA-degradation capacity (putrescine, cadaverine, and histamine) under DPD treatments compared to the absence of DPD treatment in vitro. Additionally, a significant increase in the production of AI-2 signal molecule and diamine oxidase in L. plantarum SH7 was observed with the addition of exogenous DPD (p < 0.05). In the dry-sausage model, the contents of BAs (tryptamine, 2-phenethylamine, putrescine, cadaverine, and histamine) significantly decreased with the addition of DPD (p < 0.05). Meanwhile, the sausage with 600-nM DPD exhibited the lowest cadaverine content (11.13 mg/kg), while the sausage with 900-nM DPD exhibited the lowest tryptamine, putrescine, and histamine contents (12.44, 11.15, and 13.21 mg/kg, respectively). Results suggest that an optimal concentration of exogenous DPD can enhance the capacity of L. plantarum SH7 to degrade BAs and that the degradation of BAs by L. plantarum SH7 may be dependent on the LuxS/AI-2 quorum sensing (QS) system. This study provides the theoretical basis for the development of functional starter cultures of lactic acid bacteria with BA-degradation ability based on targeted LuxS/AI-2 QS system regulation and reducing the accumulation of BAs in fermented meat products.

Purification of angiotensin converting enzyme inhibitory peptides and antihypertensive effect generated from Indonesian traditional fermented beef (Cangkuk).

Traditional fermented meat products can be considered a source of bioactive peptides. Cangkuk, a traditional Indonesian fermented beef product is one source of angiotensin converting enzyme (ACE) inhibitory peptides. This study aimed to identify ACE-inhibitory peptides from Cangkuk and analyze their antihypertensive effects. The water-soluble fraction of Cangkuk was fractionated to obtain ACE-inhibitory peptides using an ethanol solvent at several concentrations and solid-phase extraction with an OASIS HLB cartridge followed by purification with reversed-phase high-performance liquid chromatography (RP-HPLC). HPLC-MS was used to identify target peptides, followed by automatic protein sequencer analysis to detect peptide sequences. Antihypertensive effects were analyzed on the water-soluble fraction and synthesized peptides. The animal model comprised 14-16-week-old male spontaneously hypertensive rats (SHRs) (~320 g average body weight) with mean systolic blood pressures (SBPs) higher than 190 mmHg. All oral doses of peptides were 1 mL in volume. Distilled water was used as a control. The antihypertensive activities of the sample and control were observed by measuring the SBP at 0, 2, 4, 6, 8 and 24 h after oral administration. Two sequences of ACE inhibitory peptides were found, EAPLNPKANR (IC50 value of 44.6 μmol/L) and IVG (IC50 value of 97.3 μmol/L). The water-soluble fraction demonstrated an antihypertensive effect on SHRs after oral administration at 100 mg/kg body weight, maximally lowering the SBP by 14.9 mmHg 8 h after administration. The tripeptide IVG showed the highest reduction of SBP, 24.76±2.1 mmHg 8 h after administration. The decapeptide EAPLNPKANR showed the highest reduction of SBP, 21.0±1.9 mmHg, 8 h after administration. All the samples differed significantly from the control (p<0.01). Cangkuk has potential as a functional food ingredient acting as an antihypertensive agent.

Myofibrillar protein hydrolysis under hydroxyl radical oxidative stress: Structural changes and their impacts on binding to selected aldehydes

In this study, a hydroxyl radical oxidation system was established to simulate the oxidation process in fermented meat products. This system was employed to examine the structural changes in myofibrillar proteins (MPs) resulting from tryptic hydrolysis after a hydroxyl radical oxidative regime. The effect of these changes on the ability of MPs to bind selected aldehydes (3-methyl butanal, pentanal, hexanal, and heptanal) was also investigated. Moderate oxidation (H2O2 ≤ 1.0 mM) unfolded the structure of MPs, facilitating trypsin-mediated hydrolysis and increasing their binding capacity for the four selected aldehydes. However, excessive oxidation (H2O2 ≥ 2.5 mM) led to cross-linking and aggregation of MPs, inhibiting trypsin-mediated hydrolysis. The oxidised MPs had the best binding capacity for heptanal. The interaction of the oxidised trypsin-hydrolysed MPs with heptanal was driven by hydrophobic interactions. The binding of heptanal affected the structure of the oxidised trypsin-hydrolysed MPs and reduced their α-helix content.