Lipid oxidative changes in chitosan-oregano coated traditional dry fermented sausage Petrovská klobása

Essential Oils and Their Combination with Lactic Acid Bacteria and Bacteriocins to Improve the Safety and Shelf Life of Foods: A Review

The use of plant extracts (e.g., essential oils and their active compounds) represents an interesting alternative to chemical additives and preservatives applied to delay the alteration and oxidation of foods during their storage. Essential oils (EO) are nowadays considered valuable sources of food preservatives as they provide a healthier alternative to synthetic chemicals while serving the same purpose without affecting food quality parameters. The natural antimicrobial molecules found in medicinal plants represent a possible solution against drug-resistant bacteria, which represent a global health problem, especially for foodborne infections. Several solutions related to their application on food have been described, such as incorporation in active packaging or edible film and direct encapsulation. However, the use of bioactive concentrations of plant derivatives may negatively impact the sensorial characteristics of the final product, and to solve this problem, their application has been proposed in combination with other hurdles, including biocontrol agents. Biocontrol agents are microbial cultures capable of producing natural antimicrobials, including bacteriocins, organic acids, volatile organic compounds, and hydrolytic enzymes. The major effect of bacteriocins or bacteriocin-producing LAB (lactic acid bacteria) on food is obtained when their use is combined with other preservation methods. The combined use of EOs and biocontrol agents in fruit and vegetables, meat, and dairy products is becoming more and more important due to growing concerns about potentially dangerous and toxic synthetic additives. The combination of these two hurdles can improve the safety and shelf life (inactivation of spoilage or pathogenic microorganisms) of the final products while maintaining or stabilizing their sensory and nutritional quality. This review critically describes and collects the most updated works regarding the application of EOs in different food sectors and their combination with biocontrol agents and bacteriocins.

Spicy and Aromatic Plants for Meat and Meat Analogues Applications

Aromatic and spicy plants are an important factor that contributes not only to improving the taste of meat, meat products, and meat analogues, but also to increasing the nutritional value of the products to which they are added. The aim of this paper is to present the latest information on the bioactive antioxidant and antimicrobial properties of the most commonly used herbs and spices (parsley, dill, basil, oregano, sage, coriander, rosemary, marjoram, tarragon, bay, thyme, and mint) used in the meat and meat analogues industry, or proposed to be used for meat analogues.

Effect of chitosan coating incorporated with oregano or cinnamon essential oil on the bacterial diversity and shelf life of roast duck in modified atmosphere packaging

The present study aimed to investigate the effect of chitosan edible coating containing 0.15% oregano essential oil (OEO) or 0.60% cinnamon essential oil (CEO) on the quality characteristics and dynamic changes in the bacterial community of roast duck slices under modified atmosphere packaging (MAP, 30% CO₂/70% N₂) during 21 days of storage at 2 ± 2 °C. The results showed that the application of chitosan coating (CH) alone inhibited the growth of microorganisms and prevented lipid oxidation throughout storage. Moreover, the storage stability was further improved by including OEO or CEO, which lowered (P < 0.05) values for total viable count (TVC), Enterobacteriaceae, 2-thiobarbituric acid reactive substance (TBARS) and total volatile basic nitrogen (TVB-N). Based on the microbiological results, the shelf-life of CH-OEO and CH-CEO treated roast duck slices was prolonged by at least 7 days compared to that of the control. In addition, packaging types applied in this study played a major role in the bacterial community development. Notably, Vibrio spp. were the most predominant bacteria in all samples, when TVC values approached the shelf-life threshold, suggesting that this bacterium may be the main contributor to the spoilage of roast duck. The growth inhibition of Vibrio spp. in the CH-OEO and CH-CEO treatments during the early period of chilled storage might be the reason for the extension of the shelf life. Taken together, CH incorporated with OEO or CEO could be developed as prospective edible packaging materials to preserve roast duck meat.

Sustainable sources for antioxidant and antimicrobial compounds used in meat and seafood products

The contribution of food in promotion of health has become of most importance. The challenges that lie before the global food supply chain, such as climate changes, food contamination, and antimicrobial resistance may compromise food safety at international scale. Compounds with strong antimicrobial and antioxidant activity can be extracted from different natural and sustainable sources and may contribute to extend the shelf life of meat and seafood products, enhance food safety and enrich foods with additional biologically active and functional ingredients. This chapter describes the use of bioprotective cultures, essential oils, plant extracts, seaweed extracts and grape pomace compounds in production of value-added meat and seafood products with improved shelf life and safety, following the requests from the market and consumers.

Prolonged continual consumption of oregano herb interferes with the action of steroid hormones and several drugs, and effects signaling across the brain-gut axis

Herbs and spices have been used throughout human history for their medicinal qualities. The advent of cheap and readily available medicines have lessened the need for herbs and spices as traditional medicines, however, they are rapidly regaining popularity with rising interest of the general population in health, natural products and nutrition. The need for alternative medicines with antimicrobial properties, such as herbs and spices, has also come to the forefront in light of the recent bans of antibiotic use in the livestock industry, including the poultry industry. This large scale use presents an opportunity to observe nutrigenomic effects of prolonged use of herbs on a substantial number of birds fed high concentrations of these products throughout the production cycle. In this manuscript, we investigated the transcriptional effect of continual prolonged oregano supplementation on chicken ileum gene expression. Based on ileum transcriptomics, we report that continual supplementation with 2% oregano altered microbiota-gut-brain axis signalling, rearranged cancer susceptibility towards reduced steroid hormone-related cancers and altered expression of genes targeted by many registered drugs, thus likely affecting their efficiency and side effects. Transcriptional toxicology analysis indicated significant activation of Ventricular Septal Defect and Congenital Heart Disease categories. Our results, counter the notion that natural products such as oregano have the potential for little to no side-effects as they are "natural". The nutrigenomic approach of understanding benefits and side effects of the food we eat, can revolutionize disease management and therapy and have special significance in designing the diets for individuals or livestock with known disease predispositions.

Use of Turkey Meat Affected by White Striping Myopathy for the Development of Low-Fat Cooked Sausage Enriched with Chitosan

The main objective of this research was the development of a healthy meat product from turkey meat with white striping myopathy. The effect of adding different proportions of chitosan on the qualitative characteristics, sensory acceptance, and stability of cooked sausages during storage was studied. Three treatments were elaborated (control, 1.5% chitosan, and 3% chitosan), stored for 56 days, and characterized in terms of chemical composition, texture profile analysis, drip and pressure loss analysis, and sensory analysis (after processing; day 0). In the different storage periods (0 and 56 days), the pH value, color, thiobarbituric acid reactive substances (TBARS), and volatile compounds were evaluated. The results showed that the moisture content, lipids, proteins, and weight loss decreased (p < 0.05) and the ash content increased (p < 0.05) with the addition of chitosan. Similarly, the values of texture parameters (hardness, cohesiveness, gumminess, and chewiness) were higher in the sausages reformulated with chitosan than in control samples. The addition of chitosan increased the pH and yellowness (b*) values and reduced (p < 0.05) redness (a*) and lightness (L*) values. The b* values (only in reformulated sausages) and pH increased during storage, while a* showed a significant reduction after 56 storage days. Lipid oxidation (TBARS) was kept below the limits of quantification in all samples and both after processing and 56 storage days. However, when quantifying the lipid-derived volatiles, a clear antioxidant activity of chitosan was observed, which limits the release of these compounds, mainly aldehydes (hexanal and nonanal). Finally, the sensory analysis indicated that, although chitosan treatments received the lowest scores for all attributes, the reformulated samples did not differ from control sausages. Therefore, sausage containing chitosan may represent an interesting alternative for adding value to turkey meats affected by white striping myopathy and, at the same time, develop into a healthy and functional meat product increasing the proportion of fibers in one’s diet.

Contribution of surface application of chitosan-thyme and chitosan-rosemary essential oils to the volatile composition, microbial profile, and physicochemical and sensory quality of dry-fermented sausages during storage

The effect of chitosan (C), chitosan enriched with thyme (CT) or rosemary (CR) essential oils, and potassium sorbate (PS) against superficial fungal growth was investigated in fermented sausages during 3 months of storage at 4 °C. For control groups, distilled water (DW) and acetic acid (AA) were used. PS, C, CT and CR treatments inhibited fungal growth on casings while they resulted in lower Gram(+) catalase(+) cocci, Enterobacteriaceae, mold and yeast counts in sausages. Lower TBARS values were determined for CT and CR (p < .05). A total of 44 and 64 volatile compounds were identified in sausages and casings, respectively. Sausages coated with C, CT or CR had acceptable sensory attributes at the end of storage; however, DW and AA groups were rejected in the second and third month (p < .05), respectively, due to intense fungal growth which resulted in sensory defects.

Effects of chitosan as a surface fungus inhibitor on microbiological, physicochemical, oxidative and sensory characteristics of dry fermented sausages

The study aimed to improve the quality characteristics of Turkish dry-fermented sausages (sucuk) using different concentrations of chitosan (CH) coating as superficial mold inhibitor. The sausages were treated (w/w) with chitosan (0.2%, CH1; 0.5%, CH2 and 1%, CH3), potassium sorbate (20%, PS), acetic acid (1%, AA) and distilled water. Treatment with PS and CH3 resulted in a remarkable reduction of mold and yeast counts in the sausages and on casings at the end of ripening. Total aerobic mesophilic bacteria and lactic acid bacteria (LAB) varied from 7.19-7.29 to 9.01-9.27 and from 6.37-6.44 to 8.53-8.93 log CFU/g at day 0 and 12, respectively. Treatment with chitosan did not affect the natural microbiota of the sausages. Enterobacteriaceae counts were lowered from 5.79-5.89 to 2.08-2.53 log CFU/g by chitosan. Moreover, the rate of lipid oxidation in the sausages decreased by chitosan treatment. Sensory attributes were also notably enhanced in the cooked sausages treated with chitosan.

Chitosan active films containing agro-industrial residue extracts for shelf life extension of chicken restructured product

This study aimed to develop chitosan films incorporating natural antioxidants from peanut skin (EPS) and pink pepper residue (EPP) extracts, as well as to evaluate their effects on lipid oxidation, pH, color, and microbial counts of a restructured chicken product. EPS had higher phenolic content and antioxidant activity compared to EPP. When both extracts were applied to chicken meat and the chitosan films, there were no differences for color, pH and total mesophilic counts compared to control at the end of the storage period. For lipid oxidation (peroxide value and thiobarbituric acid reactive substances), both extracts proved to be as effective as butylated hydroxytoluene to maintain the oxidative stability of the chicken product. The microbial counts of psychrotrophic microorganisms were significantly lower for treatments with active films. Chitosan active films with residue extracts may maintain the quality of chicken products due to their antioxidant and antimicrobial potential.

Effect of chitosans and chitooligosaccharides on the processing and storage quality of foods of animal and aquatic origin

Purpose

– The aim of the paper is to shed light on the use of chitosans and chitooligosaccharides as biopreservatives in various foods animal. Foods of animal and aquatic origin (milk, meat, fish, eggs, sea foods, etc) become contaminated with a wide range of microorganisms (bacteria, molds and yeasts) during harvesting, transporting, processing, handling and storage operations. Due to the perishable nature of these foods, their preservation is of utmost importance. Though many synthetic chemicals are available, yet their use is quite restricted due to their hazardous effects on human health.

Design/methodology/approach

– Within the domain of food industry, traditionally chitosan is used for biopreservation of foods, which is well known for its nutritional and medicinal properties in human nutrition. However, chitooligosaccharides also possess a number of nutraceutical and health promoting properties in addition to their preservative effect and shelf-life extension of foods. In this study, the comparative effects of both chitosan and chitooligosaccharides on preservation of foods of animal and aquatic origin have been summarized.

Findings

– Though chitosan has been extensively studied in various foods, yet the use of chitooligosaccharides has been relatively less explored. Chitooligosaccharides are bioactive molecules generated from chitosan and have several advantages over the traditional use of chitosan both in food products and on human health. But unfortunately, little or no literature is available on the use of chitooligosaccharides for preservation of some of the foods of animal origin. Notable examples in this category include cheese, beef, pork, chicken, fish, sea foods, etc.

Originality/value

– This paper focuses on the effects of chitosans and chitooligosaccharides on the processing and storage quality of foods of animal and aquatic origin, which offers a promising future for the development of functional foods.

The Interaction Between Lipoxygenase-Catalyzed Oxidation and Autoxidation in Dry-Cured Bacon and a Model System

A model system was conducted to characterize the interaction between lipid autoxidation and enzyme-catalyzed oxidation in dry-cured bacon. This involved the use of a hydroxyl radical (HO•) generating system and the extraction and purification of lipoxygenases (LOX) from pork belly. The results showed that LOX activity rapidly (P < 0.05) increased during the curing of dry-cured bacon. This may be because of the hydroxyl-radical-mediated oxidation from LOX-Fe(2+) to LOX-Fe(3+), which activates LOX. In addition, experiments of the model system also showed that LOX activity could be inhibited by increasing the substrate concentration, although substrate type and concentration had no effect on autoxidation. Moreover, LOX enzyme-catalyzed oxidation and autoxidation could act synergistically to promote lipid oxidation irrespective of the substrate (linoleic or arachidonic acid). These results provide useful information for regulating lipid oxidation during the production of dry-cured pork products.