3806

3598

كارشناسي ارشد

علوم و صنايع غذايي

اصفهان : دانشگاه صنعتي اصفهان، دانشكده كشاورزي

1386

چهارده، 103، [II]ص.: مصور، جدول، نمودار

ص.ع. به فارسي و انگليسي

جواد كرامت

مهدي كديور

12/10/86

محمد فضيلتي، بهرام باني نسب

مهندسي كشاورزي

ID3598

به فارسي و انگليسي : قابل رؤيت در نسخه ديجيتال

AbstractVirgin olive oil is a foodstuff rich in natural antioxidants polyphenols and tocopherols and presence of oleic acid at significant amount in olive oil 55 83 makes it moreresistant to the oxidation process while it is also responsible for the increasing of theplasma HDL and decreasing of LDL thus it has potential health benefits and plays animportant role in the prevention of the cardiovascular diseases Dramatic increase indemand and price for olive oil has observed over the past few years that can be cause ofadultration in virgin olive oil Therefore authentication of purity is desirable So far several techniques have used to detect olive oil adultrations In this study some physical chemical and instrumental methods were used to detect the possibility of adultration inIranian olive oils by mixing of other oils specially soybean canola sunflower and olivepomace oils that are common adultrants found in virgin olive oils It was observed thatamong physical and chemical indexes iodine value and refractive index in two olive oilsamples named as A and B were significantly p 0 01 higher than reference olive oil pure olive oil and were above the official limits established for olive oil that wereconsidered as a reason for high degree of unsaturation in these oilve oils Further studieswere carried out by using of instrumental methods including gas chromatography nuclear magnetic resonance and differential scanning calorimetry Fatty acid profiles ofthe samples A and B showed higher amounts of linolenic and linoleic acids 5 68 40 94 and 6 65 55 04 respectively and significantly lower amounts of oleicacid For this resaen soybean oil was considered as a possible adultrant Because ofhigher amount of linolenic and linoleic acids in samples A and B intensity andintegrated area of signals 2 and 7 were more than other olive oil samples while in otherolive oils signal 2 was not observed and signal 7 had very low intensity These resultscould be evidents of the proportions of linolenic acyl groups higher than maximum limit about 1 were observable in HNMR spectra Crystallisation and melting curves inpure olive oil showed three peaks The largest peak that was as main peak could havebeen caused by the major group of triacylglyceroles such as OOL POO and OOO Theresults obtained from the that in samples A and B were due to the changing of FA andTAG profiles Crystallisation and melting curves were simillar to those of soybean andsunflower oils Also because of increasing in unsaturation fatty acids temperature ofpeaks oneset and offset temperatures T0 Tf clearly siffted to lower values Becauseof similarity between fatty acid profiles in pomace oilve oil and virgin olive oil using ofphysical and chemical indexes except non saponifiable compounds could not be usefulfor distinguishing between these two oils On the other hands NMR spectra crystallisation and melting curves were also similar in these samples

جواد كرامت

مهدي كديور

محمد فضيلتي، بهرام باني نسب