اﺛﺮ ﺿﺪاﮐﺴﺎﯾﺸﯽ ﻋﺼﺎرهﻫﺎي ﻣﯿﻮه ﮐﻨﺎر )Ziziphus spina-christi( و ﻫﺴﺘﻪ ﺧﺮﻣﺎ )Phoenix dactylitera( رﻗﻢ ﻣﻀﺎﻓﺘﯽ ﺑﺮ ﭘﯿﺸﺮﻓﺖ اﮐﺴﺎﯾﺶ روﻏﻦ ﺳﻮﯾﺎ

The antioxidative effect of the zizyphus fruit (Ziziphus spina-christi) and Date Seed (Phoenix dactylitera) of var. Mazafati extracts on soybean oil oxidation

ﺳﺎﺑﻘﻪ و ﻫﺪف: اﮐﺴﺎﯾﺶ روﻏﻦﻫﺎ ﻋﻼوه ﺑﺮ ﺗﻐﯿﯿﺮ وﯾﮋﮔﯽﻫﺎي ارﮔﺎﻧﻮﻟﭙﺘﯿﮑﯽ ﻣﺎده ﻏﺬاﯾﯽ، ارزش ﻏﺬاﯾﯽ و ﻋﻤﺮ ﻧﮕﻬﺪاري روﻏﻦﻫﺎ را ﮐﺎﻫﺶ ﻣﯽدﻫﺪ و ﺑﻪ دﻟﯿﻞ ﺗﻮﻟﯿﺪ ﺗﺮﮐﯿﺒﺎت ﻧﺎﻣﻄﻠﻮب در روﻏﻦ ﺑﺮاي ﺳﻼﻣﺘﯽ ﻣﺼﺮف ﮐﻨﻨـﺪﮔﺎن ﺗـﺄﺛﯿﺮ ﺳـﻮﺋﯽ دارد. در ﺣـﺎل ﺣﺎﺿـﺮ، ﺿﺪاﮐﺴﻨﺪهﻫﺎي ﺳﻨﺘﺰي داراي ﺑﯿﺸﺘﺮﯾﻦ ﮐﺎرﺑﺮد ﻣﯽﺑﺎﺷﻨﺪ، اﻣﺎ ﻣﺼﺮف آنﻫﺎ ﺑﻪ دﻟﯿﻞ ﺧﺎﺻﯿﺖ ﺳﺮﻃﺎنزاﯾﯽ رو ﺑﻪ ﮐﺎﻫﺶ ﮔﺬارده اﺳﺖ. از اﯾﻦ رو، ﺿﺪاﮐﺴﻨﺪهﻫﺎي ﻃﺒﯿﻌﯽ ﻣﺎﻧﻨﺪ ﺗﻮﮐﻮﻓﺮولﻫﺎ و ﻣﺸﺘﻘﺎت اﺳﯿﺪ آﺳﮑﻮرﺑﯿﮏ ﺑﻪ ﻋﻨﻮان ﺿﺪاﮐﺴﻨﺪهﻫﺎي ﻃﺒﯿﻌﯽ اﯾﻤـﻦ ﺑـﻪ ﻃـﻮر ﮔﺴﺘﺮده ﻣﻮرد اﺳﺘﻔﺎده ﻗﺮار ﮔﺮﻓﺘﻪاﻧﺪ. ﻫﺪف از اﯾﻦ ﻣﻄﺎﻟﻌﻪ، ﺑﺮرﺳﯽ ﻓﻌﺎﻟﯿﺖ ﺿﺪاﮐﺴﺎﯾﺸﯽ ﻫﺴﺘﻪي ﺧﺮﻣﺎ و ﻣﯿـﻮه ي ﮐﻨـﺎر و ﻫﻤﭽﻨـﯿﻦ ﺑﻬﺘﺮﯾﻦ ﻧﻤﻮﻧﻪ ﺗﺮﮐﯿﺒﯽآنﻫﺎ ﺑﺮ ﭘﯿﺸﺮﻓﺖ اﮐﺴﺎﯾﺶ روﻏﻦ ﺳﻮﯾﺎ ﻣﯽﺑﺎﺷﺪ. ﻣﻮاد و روشﻫﺎ: در اﯾﻦ ﭘﮋوﻫﺶ اﺑﺘﺪا ﺗﺎﺛﯿﺮ ﺿﺪاﮐﺴﺎﯾﺸﯽ ﻋﺼﺎرهﻫﺎي آﺑﯽ اﻧﻔﺮادي و ﺗﺮﮐﯿﺒﯽ ﮐﻨﺎر و ﻫﺴـﺘﻪ ﺧﺮﻣـﺎ در ﻏﻠﻈـﺖ ﻫـﺎي ﻣﺨﺘﻠﻒ ﻣﻮرد ﺑﺮرﺳﯽ ﻗﺮار ﮔﺮﻓﺖ. ﺳﭙﺲ ﺗﺎﺛﯿﺮ ﻋﺼﺎرهﻫﺎي آﺑﯽ ﻫﺴﺘﻪ ﺧﺮﻣﺎ و ﻣﯿﻮه ﮐﻨﺎر و ﺗﺮﮐﯿﺐ ﻣﻨﺘﺨﺐ آنﻫﺎ ﺑـﺮ اﺳـﺎس آزﻣـﻮن ﻗﺒﻠﯽ، ﺑﺮ ﭘﺎﯾﺪاري اﮐﺴﺎﯾﺸﯽ روﻏﻦ ﺳﻮﯾﺎ ﻃﯽ دوره ﻧﮕﻬﺪاري ﻣﻮرد ﻣﻄﺎﻟﻌﻪ ﻗﺮار ﮔﺮﻓﺖ. ﺑﺪﯾﻦ ﻣﻨﻈﻮر، ﻋﺼﺎرهﻫﺎي ذﮐﺮ ﺷﺪه ﺑﻪ روﻏﻦ ﺳﻮﯾﺎي ﺗﺼﻔﯿﻪ ﺷﺪه ﻓﺎﻗﺪ ﺿﺪاﮐﺴﻨﺪه اﻓﺰوده ﺷﺪﻧﺪ و ﭘﺎﯾﺪاري اﮐﺴﺎﯾﺸﯽ روﻏﻦ در دﻣﺎي 63 درﺟﻪ ﺳﺎﻧﺘﯽﮔﺮاد ﺑـﻪ ﻣـﺪت 32 روز از ﻃﺮﯾﻖ اﻧﺪازهﮔﯿﺮي ﻋﺪد ﭘﺮاﮐﺴﯿﺪ و ﻃﻮل دوره اﻟﻘﺎ و ﻫﻤﭽﻨﯿﻦ اﻧﺪﯾﺲ ﺗﯿﻮﺑﺎرﺑﯿﺘﻮرﯾـﮏ اﺳـﯿﺪ (TBA) ارزﯾـﺎﺑﯽ ﮔﺮدﯾـﺪ و ﺑـﺎ ﻓﻌﺎﻟﯿـﺖ ﺿﺪاﮐﺴﻨﺪه ﺳﻨﺘﺰي ﺑﻮﺗﯿﻠﯿﺘﺪ ﻫﯿﺪروﮐﺴﯽ ﺗﻮﻟﻮﺋﻦ (BHT) ﻣﻘﺎﯾﺴﻪ ﮔﺮدﯾﺪ. ﺗﯿﻤﺎرﻫﺎي ﻣـﻮرد اﺳـﺘﻔﺎده در آزﻣـﻮن ﺿﺪ اﮐﺴﺎﯾﺸـﯽ ﺷـﺎﻣﻞ ﻏﻠﻈﺖﻫﺎي 200 و500 ﻣﯿﮑﺮوﮔﺮم ﺑﺮ ﻣﯿﻠﯽﻟﯿﺘﺮ از ﻋﺼﺎرهﻫﺎي آﺑﯽ اﻧﻔﺮادي و ﺗﺮﮐﯿﺒﯽ ﮐﻨﺎر و ﻫﺴﺘﻪ ﺧﺮﻣﺎ و ﻧﺴﺒﺖﻫﺎي ﺗﺮﮐﯿﺒﯽ ﺑـﺮاي ﺗﺮﮐﯿﺐ دو ﻋﺼﺎره ﺑﺮ ﺣﺴﺐ درﺻﺪ ﺑﻪ ﺻﻮرت 0:100، 20:80، 40:60، 50:50، 60:40، 80:20 و 100:0 ﺑﻮدﻧﺪ. در آزﻣﻮن ﭘﺎﯾﺪاري اﮐﺴﺎﯾﺸﯽ روﻏﻦ ﺳﻮﯾﺎ ﺗﯿﻤﺎرﻫﺎي ﻣﻮرد اﺳﺘﻔﺎده ﺷﺎﻣﻞ ﻧﺴﺒﺖ 80:20 ﮐﻨﺎر و ﻫﺴﺘﻪ ﺧﺮﻣﺎ در ﻏﻠﻈﺖ 200 ﭘﯽﭘـﯽ ام و ﻫﻤﭽﻨـﯿﻦ ﭘـﻮدر ﻋﺼﺎرهﻫﺎي اﻧﻔﺮادي آنﻫﺎ در دو ﻏﻠﻈﺖ 200 و 500 ﭘﯽﭘﯽام و ﻧﯿﺰ ﺿﺪاﮐﺴﻨﺪه ﺳﻨﺘﺰي BHT در دو ﻏﻠﻈﺖ 100 و 200 ﭘﯽﭘﯽام ﺑﻮد. آزﻣﻮنﻫﺎ در ﺳﻪ ﺗﮑﺮار و ﺑﺎ اﺳﺘﻔﺎده از ﻃﺮح ﮐﺎﻣﻼ ﺗﺼﺎدﻓﯽ و در ﻗﺎﻟﺐ آزﻣﺎﯾﺶ ﻓﺎﮐﺘﻮرﯾﻞ، و ﻣﻘﺎﯾﺴﻪ ﻣﯿﺎﻧﮕﯿﻦ ﺑـﺎ آزﻣـﻮن داﻧﮑـﻦ در ﺳﻄﺢ اﺣﺘﻤﺎل 5 درﺻﺪ )0/05

Background and objectives: The oil oxidation changes the organoleptic characteristics of foods and decreases the nutritional value and shelf life of oils and is harmful to consumer health due to formation of unfavorable compounds in oil. Currently, the most widely used antioxidants are synthetic antioxidants, but their use faced some restriction due to their carcinogenic properties. Hence, natural antioxidants such as tocopherols and ascorbic acid derivatives are widely used as safe natural antioxidants. The aim of the present study was evaluation of antioxidant properties of date palm and Zizyphus extracts and their combined extract on soybean oil oxidation. Materials and methods: In this research, initially the antioxidant effect of individual and combined aqueous extract of the zizyphus fruit and date seed in different concentration was measured and then the effect of the zizyphus fruit and date seed extracts and their selected combination based on previous step, on oxidative stability of soybean oil during storage was evaluated. For this purpose, the extracts were added to free antioxidant soybean oil and oxidative stability of oil was measured at temperature of 63 °c for 32 days using peroxide index, the induction period and also thiobarbituric acid index (TBA) and was compared with synthetic antioxidant BHT. The treatments used in antioxidant experiment were the individual and combined extract of the zizyphus fruit and date seed at two different concentration of 200 and 500 ppm with different ratio of combined extract including 0:100, 20:80, 40:60, 50:50, 60:40, 80:20 and 100:0. In the soybean oil stability experiment the treatments used were ratio of the combined zizyphus fruit and date seed extract of 20:80 at concentration of 200 ppm and two concentration of 200 and 500 pp for individual extract and BHT in two concentration of 100 and 200 ppm. The results were compared in three replications using the completely randomized design, in a factorial design experiment, ANOVA analysis and Duncan test (p < 0.05) by SPSS software (version 16) and the graphs were drawn by Microsoft Excel. Results: The results of the peroxide value and TBA tests showed there was no synergistic effect in the combined extract (zizyphus fruit :date seed with the ratio of 20:80, in concentration of 200 ppm). Yet in peroxide test this extract showed a significant better effect (p < 0.05) compared to BHT, but in TBA test, it showed similar function as synthetic antioxidant BHT. In individual extract at both concentration of 200 and 500 ppm they were comparable to BHT with the concentration of 100 and 200 ppm. Conclusion: Results of present study indicates the zizyphus fruit and date seed extracts, as individual or combined extract could be used as an alternative to the synthetic antioxidant BHT.