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Öğe An alternative strategy for corn drying (Zea mays) resulted in both energy savings and reduction of fumonisins B1 and B2 contamination(Wiley, 2010) Yilmaz, Nese; Tuncel, Necati BarisP>The objectives of this study were to investigate the effect of harvest date on fumonisins contamination and to offer an alternative drying procedure with low energy costs. Corn kernel samples above 13% moisture content were dried with hot air (HA), the technique more usually utilised by farmers and compared with infrared and infrared-hot air (IR-HA) combination techniques. The effect of harvest date on fumonisin contamination was found to be significant while drying had no influence. Due to the fact that the corn remains in the field longer than necessary for economic reasons, energy expenses of the drying techniques were calculated in terms of specific energy consumption for unit of evaporated water. It was found that the energy expenses to reduce the moisture level from 15 to 13% with HA drying were higher than the expenses to reduce the moisture level from 29 to 13% with IR-HA drying combination.Öğe Drying, Energy, and Some Physical and Nutritional Quality Properties of Tomatoes Dried with Short-Infrared Radiation(Springer, 2015) Kocabiyik, Habib; Yilmaz, Nese; Tuncel, Necati Baris; Sumer, Sarp Korkut; Buyukcan, Mehmet BurakThis study was performed to determine the drying characteristics and final product quality of tomato slices dried at infrared radiation intensities of 1830, 2385, 2640, 2880, and 3165 W/m(2) and at air velocities of 1.0, 1.5, and 2.0 m/s. A comprehensive analysis of dried products was performed on their drying kinetics, drying time, specific energy consumption, shrinkage, rehydration ratio, color, vitamin C, and lycopene. The results showed that drying time was prolonged with increasing air velocity while it was shortened with increasing infrared radiation intensity. The lowest energy consumption occurred at the air velocity of 1.0 m/s and at infrared radiation intensity of 2640 W/m(2). Shrinkage and rehydration ratio varied between 0.139 from 0.203 and 2.14 from 3.40 for all the drying conditions, respectively. Delta E values varied from 5.70 to 13.06. The contents of vitamin C and beta-carotene in infrared dried tomatoes were decreased by 2-51 and 5-51 %, respectively, while there was a significant increase in lycopene content varying between 50 from 529 %. Totally, it was observed that infrared drying of tomato provided good nutrient retention and low cost of energy. Therefore, infrared radiation can be suggested in both nutritional and operational aspects in terms of drying tomato slices.Öğe Gamma-oryzanol content, phenolic acid profiles and antioxidant activity of rice milling fractions(Springer, 2011) Tuncel, N. Baris; Yilmaz, NeseThis study was aimed to determine gamma-oryzanol content and total phenolics, individual phenolic acid profile and the antioxidant activity of the free and bound extracts of rice milling fractions namely, brown rice, unpolished rice, white rice, chalky rice, raw seed and rice bran. Gamma-oryzanol content of milling fractions which is designated with a simple chromatographic method was in the range of 12.19-3,296.5 mg/kg. The whitening and polishing steps reduced approximately 94% of gamma-oryzanol of the brown rice when becoming the white rice. The contribution of bound phenolics to the total phenolic content was approximately 40%. Ferulic and p-coumaric acids were the most abundant phenolic acids in bound phenolic extracts and their amounts were 119.98 and 18.10 mu g/g, respectively, in rice bran. The best source of gamma-oryzanol, phenolics and antioxidants was clearly rice bran and followed by raw seed and brown rice.Öğe Infrared stabilization of rice bran and its effects on ?-oryzanol content, tocopherols and fatty acid composition(Wiley, 2014) Yilmaz, Nese; Tuncel, Necati Baris; Kocabiyik, HabibBACKGROUND: Rice bran is a nutritionally valuable by-product of paddy milling. In this study an experimental infrared (IR) stabilization system was developed to prevent rice bran rancidity. The free fatty acid content of raw and IR-stabilized rice bran samples was monitored every 15 days during 6 months of storage. In addition, energy consumption was determined. RESULTS: The free fatty acid content of rice bran stabilized at 600 W IR power for 5 min remained below 5% for 165 days. No significant change in -oryzanol content or fatty acid composition but a significant decrease in tocopherol content was observed in stabilized rice bran compared with raw bran. IR stabilization was found to be comparable to extrusion with regard to energy consumption. CONCLUSION: IR stabilization was effective in preventing hydrolytic rancidity of rice bran. By optimizing the operational parameters of IR stabilization, this by-product has the potential for use in the food industry in various ways as a value-added commodity. (c) 2013 Society of Chemical IndustryÖğe Middle infrared stabilization of individual rice bran milling fractions(Elsevier Sci Ltd, 2016) Yilmaz, NeseThe aim of this study was to determine the composition and hydrolytic deterioration behavior of rice bran fractions which were obtained individually from different rice whitening mills. Additionally, stabilization of these bran fractions individually with middle infrared radiation and its effects on the contents of tocopherols and gamma-oryzanol were investigated. FFA content of the crude and stabilized bran fractions that were obtained from the last whitening and polishing steps was higher either in the beginning or in the end of the storage compared to the others obtained in the first steps of whitening. Stabilization at 700 W infrared (medium-wave) power for 7.0 min provided 90 days of shelf life without a notable change in FFA content of rice bran fraction which was obtained from the first whitening step. Total tocopherol and gamma-oryzanol contents of stabilized rice bran fractions were higher than their crude counterparts. (C) 2015 Elsevier Ltd. All rights reserved.Öğe Optimizing the extraction of phenolics and antioxidants from feijoa (Feijoa sellowiana, Myrtaceae)(Springer India, 2015) Tuncel, Necati Baris; Yilmaz, NeseThis study was aimed to optimize the extraction of phenolic compounds and antioxidants in feijoa fruit by investigating the variables of solvent to sample ratio, type of solvent, extraction time and temperature with respect to the extraction efficiency. The selected optimum conditions (60 : 1 as solvent to sample ratio, 40 A degrees C temperature and 3 h extraction time) for extraction were used to extract feijoas with different solvent systems. Acetone : water (80 : 20) was chosen as the most effective solvent for extraction. Utilizing the optimum extraction conditions, total phenolic content and antioxidant activity were measured as 18.56 and 32.47 mg gallic acid equivalents per g dry weight; 165 and 465.7 milimolar Trolox equivalents per g dry weight, in flesh and the peel, respectively. Besides, syringic, ferulic, o - coumaric and trans - cinnamic acids were determined in feijoa fruit. Due to the very strong antioxidant activity found in especially feijoa peel; the extracts have the potential of being utilized in various food matrices to prevent deteriorations originated from oxidation.Öğe The effect of infrared stabilisation on B vitamins, phenolics and antioxidants in rice bran(Wiley, 2015) Yilmaz, Nese; Tuncel, Necati BarisThe effects of ten successful infrared stabilisation conditions on the content of proximate composition, dietary fibre, phytate, B vitamins, phenolics and antioxidants of rice bran were investigated. The moisture and phytate content significantly decreased in stabilised rice brans while no significant change was observed in crude fat, protein, ash and soluble and insoluble dietary fibre. Among the evaluated B vitamins, solely the content of thiamine was decreased up to 42% while the level of riboflavin, niacin, and total B-6 vitamin was not affected from infrared stabilisation (P > 0.05). The insoluble extracts contained more phenolics and antioxidants that did the soluble fractions. The effect of infrared stabilisation on the content of the phenolics and antioxidants in bound extracts was insignificant (P > 0.05). In conclusion, the authors suggest that infrared radiation can be used as a rice bran stabilisation method without causing a significant loss in the nutrients with the exception of thiamine.Öğe The effect of infrared stabilized rice bran substitution on B vitamins, minerals and phytic acid content of pan breads: Part II(Academic Press Ltd- Elsevier Science Ltd, 2014) Tuncel, N. Baris; Yilmaz, Nese; Kocabiyik, Habib; Uygur, AysenThe effect of replacing wheat flour by infrared stabilized rice bran (SRB) at the levels of 2.5, 5.0 and 10.0% on the content of thiamine, riboflavin, niacin, pyridoxamine, pyridoxine, minerals and phytic acid in white wheat, wheat bran, and whole grain wheat breads was investigated. The incorporation of SRB significantly increased the amount of the noted B vitamins, especially niacin, in all bread types (p < 0.05). Zinc, iron, potassium and phosphorus levels of the breads increased gradually and significantly with the inclusion of SRB (p < 0.05). Moreover, phytic acid content of the breads increased proportional to the SRB substitution dose (p < 0.05). (C) 2014 Elsevier Ltd. All rights reserved.Öğe The effect of infrared stabilized rice bran substitution on nutritional, sensory, and textural properties of cracker(Springer, 2014) Yilmaz, Nese; Tuncel, Necati Baris; Kocabiyik, HabibThe potential of infrared stabilized rice bran (SRB) as an ingredient in cracker formulation in terms of nutritional, sensory, and textural attributes was evaluated. Crackers were supplemented with infrared SRB at the rate of 2.5, 5, and 10 % based on flour weight. Crude fat, total ash, insoluble dietary fiber, and Zn, Fe, Ca, K, and P content of the crackers were significantly increased with increasing rice bran substitution (p < 0.05). Phytate content of the crackers that were substituted with 10 % of SRB was approximately three times higher than the control samples. Contribution of 10 % of SRB substitution to B vitamins of crackers was 46, 30, 317, and 121 % for thiamine, riboflavin, niacin, and pyridoxine, respectively. The effect on sensory scores of the panelists or textural attributes of the crackers of the replacement of refined wheat flour with SRB up to 10 % was insignificant (p > 0.05).Öğe The effect of infrared stabilized rice bran substitution on physicochemical and sensory properties of pan breads: Part I(Academic Press Ltd- Elsevier Science Ltd, 2014) Tuncel, N. Baris; Yilmaz, Nese; Kocabiyik, Habib; Uygur, AysenInfrared stabilized rice bran (SRB) substitution to white wheat, wheat bran and whole grain wheat breads at the levels of 2.5, 5.0 and 10.0% was evaluated in terms of proximate composition, crumb color, dietary fiber, texture and sensory attributes. An increasing tendency was observed in crude fat and ash content of the breads. Redness (+a*), yellowness (+b*) chroma and redness (a*/b*) values were increased gradually with the addition of SRB. Crumb color was found to be darker when 10% of SRB was added to the breads. SRB inclusion did not affect the content of soluble dietary fiber while it significantly increased the insoluble and total dietary fiber contents of the breads (p < 0.05). In general, whole grain wheat bread differed from the other bread types in terms of textural behavior. Based on the overall acceptability scores, white wheat and wheat bran breads were sensory accepted up to 10% of flour replacement with rice bran, while substitution levels higher than 2.5% negatively affected the sensory scores of whole grain wheat bread. (C) 2014 Elsevier Ltd. All rights reserved.Öğe The effect of pea (Pisum sativum L.)-originated asparaginase on acrylamide formation in certain bread types(Wiley-Blackwell Publishing, Inc, 2010) Tuncel, Necati B.; Yilmaz, Nese; Sener, ErolP>The aim of this study was to investigate the effect of pea (Pisum sativum L.)-originated asparaginase on acrylamide formation in white wheat, wheat bran and whole-grain wheat breads. Two-day germinated pea flour was used at 0%, 1%, 3% and 5% levels for each bread type. Acrylamide analysis was performed with liquid chromatography-mass spectrometry. Besides, colour and sensory properties of the breads were evaluated to search out the effects of pea flour substitution on the consumer acceptance. Reduction of acrylamide in white wheat bread was not found significant and addition of pea flour decreased the acceptance. However, it was found that acrylamide level can be reduced by 57% and 68% with addition of 5% pea flour in wheat bran and whole-grain breads, respectively, without any negative impact on colour and sensory properties.Öğe The effects of infrared and hot air drying on some properties of corn (Zea mays)(Wfl Publ, 2010) Tuncel, N. Baris; Yilmaz, Nese; Kocabiyik, Habib; Ozturk, Nilgun; Tuncel, MuzafferDue to being one of the most important dietary staple foods in the world, corn (Zea mays) has gained considerable attention. Drying is an essential procedure for safe storage of corn. The objectives of the present study were to investigate the effects of infrared (IR), hot air (HA) and infrared-hot air combined (IR-HA) drying on some properties of corn and to offer an alternative drying procedure with low energy costs. Crude protein, total carotenoid, phenolic acid composition, color parameters (L, a+, b+, chroma, Hue angle, Delta E) and energy expenses of the drying techniques in terms of specific energy consumption (SEC) for unit evaporated water were evaluated. Dent corn samples were hand harvested at regular intervals of fortnight at maturity and the initial moisture contents were 24, 16 and 15%, respectively. Preparation was included kernel manual trimming and granulating. Kernels were dried until the moisture content comes down to 13% with IR, HA and IR-HA combination techniques except for control. All drying treatments were conducted at 45 degrees C. It was observed that IR radiation did not cause any negative impact on the stated properties of corn in noted conditions. Besides, IR and IR-HA drying methods dramatically reduced the drying time. Specific energy consumption values showed that IR and IR-HA combined systems are more effective and economic when the initial moisture content of corn is above 16%. Evaporation of unit water took 12 and 40% less energy in IR drying of corn samples with the initial moisture content of 24 and 16%, respectively, as compared to HA drying alone. Hence, IR drying is considered to be a promising alternative for corn drying.Öğe The effects of middle infrared radiation intensity on the quality of dried tomato products(Wiley, 2014) Kocabiyik, Habib; Yilmaz, Nese; Tuncel, N. Baris; Sumer, Sarp K.; Buyukcan, M. Burak[Anstract Not Available]Öğe Time and temperature dependent microbiological and mycotoxin (ochratoxin-A) levels in boza(Elsevier, 2009) Uysal, Uelkue Dilek; Oncu, Elif Mine; Berikten, Derya; Yilmaz, Nese; Tuncel, Necati Baris; Kivanc, Merih; Tuncel, MuzzafferThis study describes the examination of microbiological tests and the determination of OTA in boza temperature and time dependently. Prior to the analysis, physicochemical properties of the boza samples such as moisture, total acidity as lactic acid, pH, protein amount and viscosity were investigated. The incidence of total aerobic bacteria (TAB), lactic acid bacteria (LAB), coliforms, E.coli, Salmonella, S. aureus, B. cereus, yeast and moulds were examined. E.coli, Salmonella, S. aureus and B. cereus were not found in all boza samples. Initally, Aspergillus fumigatus: Acremonium sp.; Geotrichum candidum and Geotrichum capitatum were identified in the samples. Certain extraction techniques such as direct injection, liquid-liquid and solid phase (SP) were tried for the OTA analysis. The most available way was found to be direct injection among them and the recovery was 70.56%+/- 9.80 (13.89 RSD). OTA amounts were determined in all boza samples utilizing an isocratic HPLC analysis with an ODS column. OTA was detected in only one sample as 3,58 mu g/kg and this amount is above the limits of European Commission Regulations. Time and temperature-dependent changes were investigated and insignificant variation was observed. (C) 2009 Elsevier B.V. All rights reserved.
