İç zarı ayrılmış ve ayrılmamış fındıklardan elde edilen yağların oksidasyon stabilitesinin araştırılması

Abstract

Bu calismada, 2008 ve 2009 yilarina ait iki hasat donemindeki bazi findik cesitleri (Mincane, Palaz, Giresun, Giresun Yabanisi ve Fosa) kullanilmistir. Bu orneklerden her biri hem kabuklu (kavrulmamis) hem de kabuksuz (kavrulmus) olarak gruplandirilmistir. Bu findik orneklerinin yaglari soguk ekstraksiyonla elde edilmistir. Calismada, findiklarin rutubet orani, yag orani ve beyazlama orani ve bu yaglarin serbest yag asitligi, peroksit degeri, ozgul sogurma degerleri (K232 ve K270), yag asitleri dagilimi, oksidasyon stabilitesi ve serbest radikal yakalama gucleri analiz edilmistir. Kabuklu findiklarda rutubet orani % 2.89-5.05, yag orani % 34.36-46.41; kabuksuz findiklarda rutubet orani % 1.65-3.38, yag orani % 43.46-63.67 ve findiklarda beyazlama orani her iki tip icin % 67-95 arasinda bulunmustur. Kabuklu findiklarin yaglarinda serbest yag asitligi % 0.23-1.17, peroksit degeri 0.34-5.60 meq O2/kg, ozgul sogurma degerleri (K232 ve K270) sirasiyla 1.06-2.30 ve 0.21-0.90, yag asitleri bilesiminde en fazla oleik asit, linoleik asit, palmitik asit ve stearik asit bulunmakta ve sirasiyla oranlari % 76.99-81.63, % 10.27-14.87, % 4.26-5.67 ve % 1.76-2.64’olarak bulunmustur. Kabuksuz findiklarin yaglarinda serbest yag asitligi % 0.20-0.53, peroksit degeri 0.20-2.09 meq O2/kg, ozgul sogurma degerleri (K232 ve K270) sirasiyla 1.08-1.92 ve 0.23-0.87, yag asitleri bilesiminde en fazla oleik asit, linoleik asit, palmitik asit, ve stearik asit bulunmakta ve sirasiyla oranlari % 77.01-82.18, % 9.66-14.99, % 4.26-5.69 ve % 1.71-2.49’dur. Kavurma islemi ile findiklarin yaglarinda oksidasyon stabilitesi ve serbest radikal yakalama potansiyelinde artis belirlenmistir. Kavrulmamis orneklerin yaglarinda oksidasyon stabilitesi 4.75-15.28 saat ve serbest radikal yakalama gucleri % 47.94-88.24 araliginda, kavrulmus olanlarda oksidasyon stabilitesi 6.99-15.99 saat ve serbest radikal yakalama gucu % 38.63-73.44 araliginda bulunmustur.Abstract The present study was conducted on some hazelnut species collected in two harvests of both 2008 and 2009 seasons (Mincane, Palaz, Giresun, Giresun Yabanisi and Fosa species). Each of these samples was classified as “with skin(unroasted)” and “without skin(roasted)” hazelnuts. Cold extraction method was used to extract oil from these hazelnut samples. Present study analyzed the humidity rate, oil rate and blanching rate of the hazelnuts; and free fatty acidity, peroxide value, specific absorption values (K232 and K270), fatty acid distribution, oxidation stability and free radical scavenging powers of these hazelnut oils. Humidity rate and oil rate of the unroasted hazelnuts was found to be 2.89-5.05% and 34.36-46.41%, respectively, while the humidity rate and oil rate of the roasted hazelnuts was found to be 1.65-3.38% and 43.46-63.67%, respectively. In addition, the blanching rate of the hazelnuts was found to be 67-95%. Free fatty acidity was found to be 0.23-1.17%, peroxide value to be 0.34-5.60 meq O2/kg, specific absorption values (K232 and K270) to be 1.06-2.30 and 0.21-0.90, respectively, for the oil extracted from the unroasted hazelnuts. Fatty acid concentration of this oil was recorded to be (from highest to the lowest acid amount) as follows: oleic acid, linoleic acid and stearic acid, at the rates of 76.99-81.63%, 10.27-14.87%, 4.26-5.67% and 1.76-2.64%, respectively. Free fatty acidity was found to be 0.20-0.53%, peroxide value to be 0.20-2.09 meq O2/kg and specific absorption values to be (K232 and K270) 1.08-1.92 and 0.23-0.87, respectively, for the oil extracted from the roasted hazelnuts. Fatty acid concentration of this oil was recorded to be (from highest to the lowest acid amount) as follows: oleic acid, linoleic acid, palmitic acid and stearic acid, at the rates of 77.01-82.18%, 9.66-14.99%, 4.26-5.69% and 1.71-2.49%, respectively. An increase was detected in the oxidation stability and free radical scavenging potential of the hazelnut oil after the roasting process. The oxidation stability of the oils extracted from the unroasted samples was found to be in 4.75-15.28 hours range and the free radical scavenging power to be in 47.94-88.24% range, while the oxidation stability of the oils extracted from the roasted samples was recorded to be in 6.99-15.99 hours range and free radical scavenging power to be in 38.63-73.44% range.