Reyhan Irkin

The effects of modified atmosphere gas composition on microbiological criteria, color and oxidation values of minced beef meat.

This paper reports the effects of modified atmosphere gas compositions with different concentrations of CO(2)/O(2)/N(2) on color properties (L*, a* and b* values), oxidation stability (TBARS value) and microbiological properties of minced beef meat stored at +4 °C. Sampling was carried out on the 1st, 3rd, 5th, 7th, 9th, 11th and 14th day of storage. The gas mixtures used were as follows: (i) %30O(2) + %70CO(2) (MAP1), (ii) %50O(2) + %50CO(2) (MAP2), (iii) %70O(2) + %30CO(2) (MAP3), (iv) %50O(2) + %30CO(2) + %20N(2) (MAP4), and (v) %30O(2) + %30CO(2) + %40N(2) (MAP5). Control samples (AP) were packaged under atmospheric air. Pseudomonas, lactic acid bacteria, Brochothrix thermosphacta, and Enterobacteriaceae members were monitored. Among these five modified atmosphere gas compositions, the best preservation for minced beef meat was in MAP4 gas combination maintaining acceptable color together with oxidation stability and acceptable microbial loads until the end of storage period of fourteen days.

Novel food packaging systems with natural antimicrobial agents

A new type of packaging that combines food packaging materials with antimicrobial substances to control microbial surface contamination of foods to enhance product microbial safety and to extend shelf-life is attracting interest in the packaging industry. Several antimicrobial compounds can be combined with different types of packaging materials. But in recent years, since consumer demand for natural food ingredients has increased because of safety and availability, these natural compounds are beginning to replace the chemical additives in foods and are perceived to be safer and claimed to alleviate safety concerns. Recent research studies are mainly focused on the application of natural antimicrobials in food packaging system. Biologically derived compounds like bacteriocins, phytochemicals, enzymes can be used in antimicrobial food packaging. The aim of this review is to give an overview of most important knowledge about application of natural antimicrobial packagings with model food systems and their antimicrobial effects on food products.

Inhibitory Effects of Some Plant Essential Oils Against Arcobacter butzleri and Potential for Rosemary Oil as a Natural Food Preservative

We investigated the inhibitory activity of commercially marketed essential oils of mint, rosemary, orange, sage, cinnamon, bay, clove, and cumin against Arcobacter butzleri and Arcobacter skirrowii and the effects of the essential oil of rosemary against A. butzleri in a cooked minced beef system. Using the disc diffusion method to determine the inhibitory activities of these plant essential oils against strains of Arcobacter, we found that those of rosemary, bay, cinnamon, and clove had strong inhibitory activity against these organisms, whereas the essential oils of cumin, mint, and sage failed to show inhibitory activity against most of the Arcobacter strains tested. The 0.5% (vol/wt) essential oil of rosemary was completely inhibitory against A. butzleri in the cooked minced beef system at 4°C. These essential oils may be further investigated as a natural solution to the food industry by creating an additional barrier (hurdle technology) to inhibit the growth of Arcobacter strains.

Determination of microbial contamination sources for use in quality management of cheese industry: “Dil” cheese as an example

The microbiological quality, safety and shelf-life of cheeses depend on manufacture and handling in an environment that meets basic standards for hygiene and the management of hygiene in the process. In this research contamination sources of “Dil” cheese during production in a local dairy plant in Bursa, Turkey were determined. Eighteen different control points (raw milk, pasteurized milk, heated curd, molded cheese before kneading, kneaded cheese, brine solution for kneading, thermophilic culture, rennet, calcium chloride solution, brine solution for cheese, cheese vat, workers hands, production room air, production room floor, production room wall, packaging material and packaged cheese) have been examined for the enumeration of total aerobic mesophilic bacteria, Staphylococci, Enterobacteriaceae, Salmonella spp., Escherichia coli, lactic acid bacteria, Pseudomonas spp. and yeast-moulds. It was determined that viability of lactic acid bacteria in thermophilic culture was not in high numbers and some contaminations to “Dil” cheese were detected from the starter culture. Brine solutions and rennet were contaminated with Staphylococci. Yeast and moulds in production room air were the major sources of contamination. Pasteurization and kneading in hot brine solution can eliminate some of the microorganisms but that was not sufficient in the production of Dil cheese. Finish cheese should meet specific hygienic standards, with respect to regulations post-contaminations to the cheese must be inhibited and a HACCP plan should be established during production.

Effects of organic acids to prolong the shelf-life and improve the microbial quality of fresh cut broccoli florets

This study was conducted to evaluate the effectiveness of a combination of specific organic acids for disinfecting fresh cut broccoli floret samples contaminated with Listeria monocytogenes serotype 1/2b and Salmonella enterica serovar Typhimurium. In addition, the effects of organic acids on the microbial load of broccoli samples during storage at +4 °C were determined for 7 days. The organic acids tested were acetic, benzoic, sorbic, fumaric, malic, tartaric, lactic and succinic acids and the concentrations used were 1 and 2% (w/v and v/v). L. monocytogenes and S. Typhimurium were grown on the selective media before the contamination. The broccoli samples were dipped first into the pathogen solutions containing L. monocytogenes and S. Typhimurium, then into the organic acids and subsequently counted on Oxford agar and bismuth sulphite agar, respectively. The broccoli samples dipped into the organic acids without pathogen culture were also investigated in terms of total mesophilic aerobic microorganisms,...

Influence of hot air drying on phenolic compounds and antioxidant capacity of blueberry ( Vaccinium myrtillus ) fruit and leaf

The present study was undertaken to assess the effects of hot air drying on phenolic compositions, total phenolic (TP) content, total anthocyanin (TA) content, as well as antioxidant capacities of methanol extracts from blueberry ( Vaccinium myrtillus ) fruit and leaf introduced in Kapidag region of Turkey climate conditions. A total of twenty-two phenolic standards were screened by HPLC, total phenols were measured by spectrophotometric methods, antioxidant capacity was determined using DPPH, CUPRAC, ABTS, and FRAP assays in the blueberry fruit and leaf extracts. Analysis by HPLC revealed that fruit extracts have different phenolic profiles due to drying process and contain syringic acid, myricetin, naringin, (-)-epicatechin, and malvidine-3-O-glucoside chloride as the main compounds. Leaf extracts had higher resveratrol concentrations than fruit extracts. The TP and TA contents gradually increased when the blueberry fruits were dried under hot air condition. The fresh and dried blueberry fruit and leaf extracts showed similar antioxidant capacity values. Significant relationships between antioxidant capacity and TP were found.