Levent Akkaya

Effects of packaging method and storage time on the chemical, microbiological, and sensory properties of Turkish pastirma : A dry cured beef product

The effects of packaging method (aerobic packaging (AP), vacuum packaging (VP) or modified atmosphere packaging (MAP)), the form of pastirma (sliced or non-sliced) and storage time (0, 15, 30, 60, 90 or 120 days) on the chemical, microbiological and sensory properties of a Turkish pastirma were investigated. Overall, MAP preserved chemical, microbiological and sensory properties of Turkish pastirma better than AP or VP. Very high correlation coefficients (almost all >0.90) were observed between subjective quality parameters (sensory properties) and objective quality parameters (TBARS, hexanal content, L(∗), a(∗), and b(∗)), which suggests that sensory panel was able to determine the quality changes over storage time precisely. Based on the results of this study, MAP should be the preferred choice of packaging in order to preserve overall quality of Turkish pastirma and its implication for pastirma packaging may increase pastirmas current share in the processed meat product market.

Effect of ground poppy seed as a fat replacer on meat burgers

Poppy seed paste was used in koefte production as an animal fat replacer and efficacy of using poppy seed was investigated. The use of ground poppy seed in formulation of meat burgers had no effect on the moisture content of uncooked meat burgers; however, it did have a significant effect (p<0.05) on the fat content of meat burgers. Ground poppy seed addition significantly affected (p<0.05) cooking yield, moisture retention, and fat retention of meat burgers. Ground poppy seed addition significantly decreased (p<0.05) saturated fatty acid contents as the amount of ground poppy seed increased in meat burgers. A strong significant decrease (p<0.05) on the cholesterol content of meat burgers with ground poppy seed addition was observed. Samples having 20% ground poppy seed had significantly better texture and juiciness score (p<0.05) than any other sample which could be explained by increased moisture retention. Replacing animal fat with ground poppy seed paste is effective and may pave the way for an innovative meat product.

Effects of dry, vacuum, and special bag aging; USDA quality grade; and end-point temperature on yields and eating quality of beef Longissimus lumborum steaks

This study evaluated the effects of three aging methods: (dry (D), wet (W), and special bag (SB)); two quality grades [USDA Choice((≥Small(50) marbling) and Select); and two cooked end-point temperatures (62.8 °C and 71.1 °C) on physico-chemical traits of instrumental tenderness, color, and sensory properties of Longissimus lumborum beef muscle. Dry-aged loins had higher (P<0.0001) weight loss than W or SB aged loins. However, D and SB aged loins had similar (P>0.05) combined losses. W aged loins had higher (P<0.01) L* values than D or SB aged loins. Warner-Bratzler shear force of steaks was not affected (P>0.05) by aging method or quality grade but increased (P<0.0001) as end-point temperature increased. Sensory panel evaluation also showed no effect (P>0.05) of aging method or quality grade on myofibrillar tenderness, juiciness, connective tissue amount, overall tenderness or off flavor intensity. Steaks cooked to 62.8 °C were juicier (P<0.05) than those cooked to 71.1 °C. Neither D nor SB aging had advantages over W aging.

Effects of blade tenderization, aging method and aging time on meat quality characteristics of Longissimus lumborum steaks from cull Holstein cows ☆

The effects of blade tenderization (BT), two aging methods (dry (D) and wet (W)), and aging time (2 and 23 d) on tenderness, color, and sensory properties of Longissimus lumborum muscles from 12 cull Holstein cows were evaluated. Dry-aged loins had higher combined trim and aging losses than control (C) for both D- and W-aging, mostly because of excess trim losses. BT steaks had WBSF of 33.13 N while C steaks had WBSF of 41.46 N (P=0.09). Aging decreased WBSF. Blade tenderized steaks had higher cook loss than C steaks. Aging, W-aging, and BT×W-aging improved myofibrillar (sensory) tenderness scores. Aging and/or BT improves sensory panel tenderness cull cow Longissimus lumborum steaks. Aging and blade tenderization combined can increase tenderness and value of Longissimus steaks from cull Holstein cows.

Growth-Death Kinetics of Listeria Monocytogenes in Strained Yogurt

In this research, viability of Listeria monocytogenes was studied in strained yogurt (Turkish name: Torba yogurt) samples prepared in laboratory conditions and contaminated with various levels of L. monocytogenes before and after incubation. When strained yogurt samples (pre-incubation inoculation, A1 and post-incubation inoculation, B1) were contaminated with a 106 cfu/ml level of L. monocytogenes, their pH value reached to 4.08, and the presence of L. monocytogenes was defined only by using the enrichment method at the 30th day of the storage at the pH of 3.55, since the resistance of the bacteria had been lost in those yogurts. However, L. monocytogenes was completely inhibited at the 7th day of the storage for the strained yogurt samples (pre-incubation inoculation, A2 and post-incubation inoculation, B2) contaminated with the level of 104 cfu/ml when the pH value was 3.58. As a result, it can be stated that viability of Listeria monocytogenes may not be possible if the pH of the yogurt is around the ≤3.59 after the 7th day of the storage.

Enterotoxin production by Staphylococcus aureus (A, B, C, D) during the ripening of sucuk (Turkish dry-fermented sausage)

This study was conducted to determine the capability of Staphylococcus aureus to produce toxins in Turkish sucuk. For this purpose, the ability of four different reference strains of S. aureus (i.e., SEA 10652 FDA 196E, SEB 10654 FDA 243, SEC 10655 137, and SED 10656 494) to produce A-, B-, C-, and D-type toxins, respectively, was investigated during the fermentation period of Turkish sucuk by inoculating sucuk batter with these strains at 105 CFU/g level. As a result, no SEA, SEB, and SEC toxins were detected in the A, B, and C groups, respectively, during fermentation. In group D, SED was detected after 24 h and at the 3, 7, and 12 days of ripening. In conclusion, these results indicate that Turkish sucuk may pose an important health risk related to possible contamination with S. aureus (SED) during the production processes.

Determination of Microbiological, Physico-Chemical Properties and Distribution of Lactic Acid Bacteria of Afyon Tulum Cheese

Anahtar kelimeler Peynir Afyon Tulum Peyniri Laktik Asit Bakterileri Ozet Yapilan bu calismada Afyonkarahisar ilinde uretilen Afyon Tulum Peyniri’nin mikrobiyolojik ve fizikokimyasal ozellikleri ile peynirde bulunan laktik asit bakterileri arastirilmistir. Sonuc olarak; toplam aerob mezofilik bakteri, MRS Agarda ureyen Laktik asit bakterileri (LAB), Lactococcus spp., Enterobacteriacea, Koliform, E. coli, Enterokok, Mikrokok/Staphilokok, Maya/Kuf, proteolitik bakteri, lipolitik bakteri ve psikrofilik bakteri bakteri sayilari oratama sirasiyla 6.60, 6.36, 5.72, 2.19, 1.23, 0.65, 2.08, 2.91, 2.75, 2.55, 2.94 ve 3.92 log kob/g olarak tespit edilmistir. Afyon Tulum Peyniri orneklerinde %53,01 Lactobacillus spp., %12.04 Lactococcus spp., %8.43 Leuconostoc spp., %1.20 Pediococcus spp. ve %25.30 Enterococcus spp. izole edilmis. En yuksek oranda %15.66’si Lactobacillus paracasei ssp paracasei, identifiye edilmistir. Fiziko-Kimyasal analizlerde kuru madde (%), Yag (%), Protein (%), Kul (%), Tuz (%), Asitlik (% LA), pH ve aw degerleri sirasiyla ortalama 53.69, 25.68, 22.48, 4.62, 4.02, 0.51, 5.27 ve 0.85 olarak saptanmistir. Sonuc olarak kimyasal analiz bulgularina gore Afyon Tulum Peyniri iyi bir besin kaynagi olarak degerlendirilebilir. Analize alinan Afyon Tulum Peyniri orneklerinin mikrobiyolojik ve fiziko-kimyasal ozellikleri arasinda onemli farkliliklar tespit edilmistir. Bu durum uretiminde tam bir standardizasyonun olmamasindan olabilir. Buna bagli olarak Afyon Tulum Peynirinin uretiminde bir ornekliginin saglanmasi ve kalitesinin arttirilmasi icin uretiminin standart ve hijyenik kosullarda yapilmasi, uretimin modernize edilerek standardizasyon saglanmasi gerekmektedir.

Antibacterial Activity of Turkish Endemic Sideritis Akmanii (Lamiaceae)

Antibacterial activity of Sideritis akmanii Z. Aytac, M. Ekici and A. Donmez extracts was investigated by disc diffusion methods against Aeromonas hydrophila, Salmonella typhimurium, Escherichia coli O157:H, Bacillus subtilis, Staphylococcus aureus, Listeria monocytogenes, Pseudomonas aeruginosa, Bacillus cereus, Klebsiella pneumoniae, Yersinia enterocolitica, Saccharomyces cerevisiae, and Candida albicans. Different concentrations of Sideritis akmanii oil posses a significant antibacterial acitivity against Bacillus subtilis, Bacillus cereus, Aeromonas hydrophila, and Pseudomonas aeruginosa, but have no effect on yeasts. This plant can be used as a food additive and traditional medicine. ABSTRACT