Consumer's evaluation of the effects of gamma irradiation and natural antioxidants on general acceptance of frozen beef burger

Decontamination of Escherichia coli on dried onion flakes and black pepper using Infra-red, ultraviolet and ozone hurdle technologies

Among spices, onion flakes (OF) and black pepper (BP) are commonly used ingredients in domestic cooking; however, spices have been shown to be highly contaminated with pathogenic bacteria and bacterial spores. A novel method applying a treatments of Ozone Ultraviolet (UV, 255nm) and Infra-red (IR) light in different combinations was assessed for its efficiency in decontaminating OF and BP. In this study, untreated samples, as purchased, were inoculated with 9.5 × 10⁵ cfu/mL Escherichia coli (MG1655) and exposed to each treatment alone and in combination of ozone sequentially followed by UV/IR, and UV/IR combined followed sequentially by ozone. A difference in response towards the treatment was shown among the types of spices, with a high efficacy for BP. Typically 3 log reductions were observed for ozone, UV and IR. The sequential treatments of ozone with UV and IR combined gave improved results than individual ones, with 99.99% of E. coli inactivation, and a shorter exposure duration with ozone (2.5 and 5 min) and UV and IR (2.5 and 5 min). The combined effect (ozone 2.5 min, UV and IR 10 min) yielded a log reduction of 2.69 and 4.20 for OF and BP respectively, greater than the additive effect of the individual treatments alone. The IR lamp was modulated to reduce excessive temperature rise. This novel prototype was shown to be very effective in decontaminating spices. Further studies should be conducted to validate the effectiveness of this method on decontamination of various bacterial strains.

Sensory Analysis in Assessing the Possibility of Using Ethanol Extracts of Spices to Develop New Meat Products

The food industry has endeavoured to move toward the direction of clean labelling. Therefore, replacing synthetic preservatives with natural plant extracts has gained significant importance. It is necessary to determine whether products enriched with such extracts are still accepted by consumers. In this study, consumer tests (n = 246) and sensory profiling were used to assess the impact of ethanol extracts of spices (lovage, marjoram, thyme, oregano, rosemary, and basil; concentration 0.05%) on the sensory quality of pork meatballs and hamburgers. The desirability of meat products with spice extracts to consumers depended on the added extract. The highest scores were for products with lovage extract, whose sensory profile was the most similar to the control sample without the addition of an extract (with higher intensity of broth taste compared with the others). Products with rosemary and thyme extracts were characterised by lower desirability than the control. This was related to the high intensity of spicy and essential oil tastes, as well as the bitter taste in the case of products with thyme. The studied extracts of spices allow for the creation of meat products (meatballs and hamburgers) with high consumer desirability, however, the high intensity of essential oil and spicy tastes might be a limitation.

Evaluating the Antibacterial Properties of Polyacetylene and Glucosinolate Compounds with Further Identification of Their Presence within Various Carrot (Daucus carota) and Broccoli (Brassica oleracea) Cultivars Using High-Performance Liquid Chromatography with a Diode Array Detector and Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry Analyses

Ongoing consumer concerns over using synthetic additives in foods has strongly influenced efforts worldwide to source suitable natural alternatives. In this study, the antibacterial efficacy of polyacetylene and glucosinolate compounds was evaluated against both Gram positive and Gram negative bacterial strains. Falcarinol [minimum inhibitory concentration (MIC) = 18.8-37.6 μg/mL] demonstrated the best overall antibacterial activity, while sinigrin (MIC = 46.9-62.5 μg/mL) was the most active glucosinolate compound. High-performance liquid chromatography with a diode array detector analysis showed falcarinol [85.13-244.85 μg/g of dry weight (DW)] to be the most abundant polyacetylene within six of the eight carrot (Daucus carota) cultivars investigated. Meanwhile, sinigrin (100.2-244.3 μg/g of DW) was the most abundant glucosinolate present within the majority of broccoli (Brassica oleracea) cultivars investigated using ultra performance liquid chromatography-tandem mass spectrometry analysis. The high abundance of both falcarinol and sinigrin within these respective species suggests that they could serve as potential sources of natural antibacterial agents for use as such in food products.

Effect of incorporation of Cyperus rotundus L. rhizome powder on quality attributes of minced beef meat

The primary objective of this study was to investigate the biological effectiveness of C. rotundus rhizome powder (CRRP) in improving the quality, storability, and safety of minced beef meat. CRRP was analyzed for its flavonoid and polyphenol content, antioxidants and antimicrobial activity, and its effect on the chemical properties, microbiological and sensory quality of minced beef meat. The results revealed that CRRP had a flavonoid and polyphenol contents of 24.30 mg CE/g and 353.10 mg GAE/g, respectively. The aqueous extract of CRRP showed inhibition zones of 16.3 and 11.7 mm against E. coli and S. aureus, respectively. The CRRP exhibited greater increase in TRPA, chelation of Fe²⁺ ions, and scavenging of H₂O₂ with the increase in CRRP extract concentration. Incorporation of various concentration of CRRP in minced beef meat significantly affected the physicochemical properties, microbial load, and sensory quality of the product. The effect was concentration dependent, and the highest level of CRRP (5 %) was more effective in retarding microbial growth and reducing peroxidation, but it negatively affected the sensory quality of the product. Therefore, CRRP at 2.5 % concentration was recommended as a functional additive to preserve minced meat.

Effect of Oregano Essential Oil (Origanum vulgare subsp. hirtum) on the Storage Stability and Quality Parameters of Ground Chicken Breast Meat

A study was conducted to investigate the effect of oregano essential oil on the oxidative stability and color of raw and cooked chicken breast meats. Five treatments, including (1) control (none added); (2) 100 ppm oregano essential oil; (3) 300 ppm oregano essential oil; (4) 400 ppm oregano essential oil; and (5) 5 ppm butylated hydroxyanisole (BHA), were prepared with ground boneless, skinless chicken breast meat and used for both raw and cooked meat studies. For raw meat study, samples were individually packaged in oxygen-permeable bags and stored in a cold room (4 °C) for 7 days. For cooked meat study, the raw meat samples were vacuum-packaged in oxygen-impermeable vacuum bags and then cooked in-bag to an internal temperature of 75 °C. After cooling to room temperature, the cooked meats were repackaged in new oxygen-permeable bags and then stored at 4 °C for 7 days. Both raw and cooked meats were analyzed for lipid and protein oxidation, volatiles, and color at 0, 3, and 7 days of storage. Oregano essential oil significantly reduced (p < 0.05) lipid and protein oxidation, and improved color stability of raw and cooked meat. However, oregano oil at 400 ppm showed the strongest effect for all these parameters. Hexanal was the major aldehyde, which was decreased significantly (p < 0.05) by oregano oil treatment, in cooked meat. Overall, oregano essential oil at 100–400 ppm levels could be a good preservative that can replace the synthetic antioxidant in chicken meat.

The use of natural herbal extracts for improving the lipid stability and sensory characteristics of irradiated ground beef

Ground Longissimus dorsi of beef were treated with herbal extracts of marjoram, rosemary and sage at concentration of 0.04% (v/w), radiation (2 or 4.5 kGy) or their combination. Treated samples were stored at 5°C and analyzed periodically for thiobarbituric acid reactive substances (TBARS), sensory characteristics and psychrotrophic bacterial counts during storage for 41 and 48 days for samples treated at 2 and 4.5 kGy respectively. Results demonstrated a significant benefit of the addition of herbal extracts to the ground beef prior to irradiation. All three extracts significantly (P<0.05) lowered the TBARS values and off-odor scores and significantly (P<0.05) increased color and acceptability scores in all samples with marjoram being the most effective. The combination treatment with herbal extracts plus irradiation resulted in extension of the shelf life of samples treated with 2 kGy by one week and samples treated with 4.5 kGy by two weeks, over that treated with irradiation alone. In conclusion, the addition of herbal extracts can minimize lipid oxidation, improve color and decrease off-odor production in irradiated ground beef.