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Öğe Drying Characteristics and Quality Parameters of Microwave-Dried Grated Carrots(Springer, 2012) Arikan, Mehmet Fatih; Ayhan, Zehra; Soysal, Yurtsever; Esturk, OkanThe effectiveness of various microwave-convective drying treatments was compared with convective drying to determine the most favourable treatments in terms of drying kinetics, specific energy consumption and dried product quality of grated carrots. The quality of the dried products differed among drying treatments depending on the microwave power level, pulse ratio and drying temperature. The intermittent microwave-convective drying at ambient temperature with a pulse ratio of 3.0 at 2.23 W g(-1) provided considerable savings in drying time and specific energy consumption when compared to convective drying and produced high-quality product with better physical (colour and texture) and sensory attributes for carrots. The intermittent microwave-convective drying conducted at lower drying temperature with relatively long power-off time resulted in a more stable and gentle drying process and could be preferred to produce high-quality products.Öğe Drying of sage (Salvia officinalis L.) inflorescences by intermittent and continuous microwave-convective air combination(Gaurav Soc Agricultural Research Information Centre-Aric, 2011) Esturk, Okan; Arslan, Mehmet; Soysal, Yurtsever; Uremis, Ilhan; Ayhan, ZehraThe effect of microwave-convective air (M-CA) drying (continuous and intermittent) and convective air (CA) drying of sage (Salvia officinalis L.) inflorescences on drying kinetics and essential oil content was studied. For M-CA drying, four pulse ratio levels (PR1, PR2, PR3 and PR4) at 25 degrees C drying air temperature were used. The average drying rates were 0.211, 0.105, 0.067 and 0.053 kg H2O/kg DM/min for PR1, PR2, PR3 and PR4, respectively. The experimental data were fitted to nine different moisture ratio (MR) models to describe the drying kinetics under various drying conditions. Page model was found satisfactory to describe the drying curves of sage inflorescences. The total quantity of essential oils of sage inflorescences decreased considerably during M-CA drying, whereas the loss of essential oils was limited during CA drying. Compared to shade drying, two essential oil components, sabinene and p-cymene, were lost during CA drying. On the other hand, in addition to these two, alpha-pinene, campene, beta-pinene, limonene, gamma-terpinene, camphor, bornyl acetate, alpha-copaene, gamma-cadinene, delta-cadinene and caryophyllene oxide were disappeared during M-CA drying. M-CA drying may not be proper technique for drying of sage inflorescences when essential oil content is important.Öğe Drying Properties and Quality Parameters of Dill Dried with Intermittent and Continuous Microwave-convective Air Treatments(Ankara Univ, Fac Agr, 2010) Esturk, Okan; Soysal, YurtseverIn this study, influence of various microwave-convective air drying applications on drying kinetics, color and sensory quality of dill leaves (Anethum graveolens L.) were investigated. In general, increasing the drying air temperature decreased the drying time, and increased the drying rate. Increasing microwave pulse ratio increased the drying time. Page, Logarithmic, Midilli et al, Wang & Singh and Logistic models were fitted to drying data and the Page model was found to satisfactorily describe the microwave-convective air drying curves of dill leaves. Comparing to the fresh dill, lightness (L*), greenness (-a*) and yellowness (+b*) decreased for all drying applications. The deviation from fresh product color (Delta E*) increased as pulse ratio increased and drying air temperature decreased. Considering the product quality, continuous microwave-convective air drying combinations gave better results than intermittent microwave-convective air drying in terms of color and sensory evaluation results.Öğe EFFECT OF MODIFIED ATMOSPHERE PACKAGING AND STORAGE TIME ON PHYSICAL AND SENSORY PROPERTIES OF SLICED SALAMI(Wiley, 2009) Esturk, Okan; Ayhan, ZehraThe objective of this study was to investigate the quality properties of sliced and modified atmosphere-packaged salami during refrigerated storage. Salami was sliced and packaged under air and three modified atmosphere packaging (MAP) compositions (100% N-2; 50% CO2, 50% N-2; 5% O-2, 25% CO2, 70% N-2) in polypropylene trays sealed with polyethylene terepthalate/polyvinylidene chloride/oriented polypropylene. Headspace oxygen and carbon dioxide (%), physical (color and texture), chemical (pH) and sensory properties were analyzed for 20 days at 4C. The results showed that CO2 concentration (%) decreased after 5 days of storage for MAP applications with high CO2, which was attributed to the solubility of CO2 in the salami. The pH did not significantly change during storage at all applications (P > 0.05). While L values increased, a and b values decreased during storage. The MAP applications with no oxygen received higher panelist scores and provided better quality characteristics than air and 5% O-2, 25% CO2, 70% N-2 for 15 days.Öğe Intermittent and Continuous Microwave-Convective Air-Drying Characteristics of Sage (Salvia officinalis) Leaves(Springer, 2012) Esturk, OkanThe effect of microwave-convective air-drying (continuous and intermittent) and convective air-drying of sage (Salvia officinalis) on color and essential oil content were studied. For microwave-convective air-drying, four pulse ratio levels (PR1, PR2, PR3, and PR4) at 25 A degrees C drying air temperature were used and the average drying rates were 0.404, 0.158, 0.114, and 0.085 kg H2O kg(-1) DM min(-1) for PR1, PR2, PR3, and PR4, respectively. For convective air-drying, two drying temperatures of 40 and 50 A degrees C were examined and the average drying rates were 0.005 and 0.006 kg H2O kg(-1) DM min(-1) for 40 and 50 A degrees C, respectively. The experimental data were fitted to 11 different moisture ratio models to describe the drying kinetics under various drying conditions. Page model was found satisfactory to describe the drying curves of sage leaves. Comparing with the fresh sage, lightness (L*), greenness, and yellowness decreased for all drying applications. Lightness, greenness, and yellowness of the convective air-dried sage leaves were higher than those of microwave-convective air-dried sage leaves. The deviation from fresh product color (Delta E*) increased as the pulse ratio or the drying air temperature increased. The total quantity of essential oils of sage decreased considerably during microwave-convective air-drying whereas the loss of essential oils was limited during air-drying.Öğe Modified Atmosphere Packaging of Kabaasi Apricot (Prunus armeniaca L. 'Kabaasi'): Effect of Atmosphere, Packaging Material Type and Coating on the Physicochemical Properties and Sensory Quality(Springer, 2012) Muftuoglu, Fatin; Ayhan, Zehra; Esturk, OkanEffects of modified atmosphere, packaging material and coating on the physicochemical properties and sensory quality of 'KabaaAYA +/-' apricot were studied. Apricots were coated with 5% NatureSealA (R), packaged under active (5% oxygen, 10% carbon dioxide) or passive atmospheres using polypropylene trays sealed with cast polypropylene or biaxially oriented polypropylene and stored at 4 A degrees C for 42 days. The colour values (L*, C* and HA degrees) significantly decreased after 28 days of storage at all applications (P a parts per thousand currency signaEuro parts per thousand 0.05). For packaged fruit, mass loss was less than 1%; however, unpackaged apricots lost 57% of their initial fresh mass until the end of storage. In general packaging material, atmosphere and coating had no significant effect on chemical attributes (pH, antioxidant activity and total carotenoid content). Physicochemical characteristics and sensory quality of uncoated and coated apricots were preserved for 28 days under active or passive modified atmosphere packaging using biaxially oriented polypropylene or cast polypropylene film. However, shelf life of unpackaged fruits was limited to less than 7 days.Öğe Modified Atmosphere Packaging of Napoleon Cherry: Effect of Packaging Material and Storage Time on Physical, Chemical, and Sensory Quality(Springer, 2012) Esturk, Okan; Ayhan, Zehra; Ustunel, Mehmet AliEffects of modified atmosphere and polymeric packaging material on the physical (mass loss, color, firmness), chemical (pH, total titratable acidity, total soluble solid, total phenolic content, total anthocyanin content), and sensory quality of Napoleon cherry (Prunus avium L. Napoleon) were studied. While lightness (L*) remained fairly unchanged, redness (a*), yellowness (b*), and chroma (C*) decreased during a 42-day storage period, resulting in darker fruit. Firmness did not differ significantly from the initial values (P a parts per thousand currency signaEuro parts per thousand 0.05) after 42 days of storage at 0A degrees C. pH increased for all treatments over the storage period. In general, total titratable acidity increased during the first 2 weeks, and then decreased afterwards. Packaging significantly reduced mass losses, which were 24.08%, 0.50%, 0.39%, and 0.81% for control (unpackaged), polypropylene tray/biaxially oriented polypropylene film (PP/BOPP), polypropylene tray/cast polypropylene film, and polyvinyl chloride-polyethylene tray/polyethylene terephthalate-polyethylene films, respectively. Modified atmosphere packaging was found beneficial on extending the shelf life of fruit during storage. The shelf life of Napoleon cherries was suggested as 28 days for packaged samples and 14 days for unpackaged samples at 0A degrees C. Samples packaged with PP/BOPP under 21% O-2 79% N-2 preserved their physical, chemical, and sensory quality better than other treatments.Öğe Overall Quality and Shelf Life of Minimally Processed and Modified Atmosphere Packaged Ready-to-Eat Pomegranate Arils(Wiley, 2009) Ayhan, Zehra; Esturk, OkanMinimally processed ready-to-eat pomegranate arils have become popular due to their convenience, high value, unique sensory characteristics, and health benefits. The objective of this study was to monitor quality parameters and to extend the shelf life of ready-to-eat pomegranate arils packaged with modified atmospheres. Minimally processed pomegranate arils were packed in PP trays sealed with BOPP film under 4 atmospheres including low and super atmospheric oxygen. Packaged arils were stored at 5 degrees C for 18 d and monitored for internal atmosphere and quality attributes. Atmosphere equilibrium was reached for all MAP applications except for high oxygen. As a general trend, slight or no significant change was detected in chemical and physical attributes of pomegranate arils during cold storage. The aerobic mesophilic bacteria were in the range of 2.30 to 4.51 log CFU/g at the end of the storage, which did not affect the sensory quality. Overall, the pomegranate arils packed with air, nitrogen, and enriched oxygen kept quality attributes and were acceptable to sensory panelists on day 18; however, marketability period was limited to 15 d for the low oxygen atmosphere. PP trays sealed with BOPP film combined with either passive or active modified atmospheres and storage at 5 degrees C provided commercially acceptable arils for 18 d with high quality and convenience.Öğe Pesticide residue analysis in parsley, lettuce and spinach by LC-MS/MS(Springer India, 2014) Esturk, Okan; Yakar, Yasin; Ayhan, ZehraIn this study, pesticide residues in parsley, lettuce and spinach (120 samples) were analyzed by the application of liquid chromatography-tandem mass spectrometry (LC-MS/MS). All samples of spinach, parsley or lettuce contained residues of three or more active substances. In parsley, carbendazim (100.0%), dichlorvos (100.0%), fenarimol (40.0%), pendimethalin (95.0%), in lettuce, diazinon (30.0%), dichlorvos (100.0%), pendimethalin (92.5%) phenthoate (12.5%), and in spinach, carbendazim (45.0%), cymoxanil (85.0%), dichlorvos (100.0%) and fenarimol (85.0%) were the significant active compounds. The maximum residue limits were exceeded in 28, 20 and 40 samples of parsley, lettuce and spinach, respectively. The results showed that there was a high occurrence of pesticide residues in parsley, lettuce and spinach samples from Hatay province, in which most of them were prohibited from use in Turkey for these vegetables. The contamination levels of these residues may be considered a serious public health problem according to the maximum residue limits (MRLs) of Turkey and the European Union (EU).Öğe Production and Application of Active Packaging Film with Ethylene Adsorber to Increase the Shelf Life of Broccoli (Brassica oleracea L. var. Italica)(Wiley-Blackwell, 2014) Esturk, Okan; Ayhan, Zehra; Gokkurt, TolgaBroccoli (Brassica oleracea L. var. Italica) florets were packaged in low-density polyethylene (LDPE) bags with or without ethylene adsorber under passive modified atmosphere and then stored at 4 degrees C for 20days. LDPE films with (8% Tazetut (R) masterbatch, M2) or without ethylene adsorber (M1) were tested. The effects of modified atmosphere packaging treatments on gas concentrations (O-2, CO2 and ethylene) in the headspace, the mass loss, colour, texture, pH, total soluble solids, chlorophyll content, total phenolic content and sensory quality of packaged broccoli were determined by comparing with unpackaged (control) florets. Results revealed that deterioration occurred quickly in control broccoli, manifested mainly by mass loss, chlorophyll degradation and stem hardening. Also, it was found unacceptable by sensory panel after 5days. Conversely, in those florets packaged under modified atmosphere packaging, especially for LDPE with ethylene adsorber (M2), all changes related with loss of quality were significantly reduced and delayed with time. Additionally, total soluble solids and total phenolic content remained almost unchanged during the whole period. Ethylene concentration was determined as 61.8ppm in M1 and 0.33ppm in M2, respectively, at the end of the storage. Thus, broccoli packaged with M2 films had prolonged storability up to 20days with high quality attributes, this period being only 5days in unpackaged control broccoli. Oxygen concentration decreased below 1% after 5days of storage in M1, and the shelf life of broccoli in these bags was limited to 5days because of risk for anaerobic fermentation. Copyright (c) 2013 John Wiley & Sons, Ltd.
