نوع مقاله : مقاله پژوهشی

نویسندگان

1 عضو هیات علمی مرکز تحقیقات کشاورزی و منابع طبیعی استان فارس

2 دانشیار بخش ماشین آلات دانشکده کشاورزی دانشگاه شیراز

3 استادیار پژوهشی مرکز تحقیقات کشاورزی و منابع طبیعی استان فارس

4 مربی پژوهشی مرکز تحقیقات کشاورزی و منابع طبیعی استان فارس

چکیده

هدف از اجرای این پروژه تعیین شرایط بهینة خشک کردن دانة انار با خشک‌کن خورشیدی است.  در این تحقیق از یک خشک‌کن خورشیدی کابینتی به صورت فعال و مختلط استفاده شد.  تیمارها با استفاده از روش سطح پاسخ در 9 حالت مختلف در نظر گرفته شدند که تیمار مرکزی (3 متر‌بر‌ثانیه سرعت جریان هواو 2 سانتی‌متر ضخامت) 5 بار تکرار شد.  در این تحقیق از دانه‌های انار رقم بریت استفاده شد و نمونه‌ها تا رسیدن رطوبت آنها به تقریبا 10 درصد خشک شدند.  مدت زمان خشک شدن، ویتامین ث، رنگ، اسیدیته، و وضعیت میکروبی نمونه‌ها بررسی شد.  اثر ضخامت محصول و سرعت عبور هوا بر زمان خشک شدن، و دیگر عامل‌های کیفی ذکر شده، به جز اسیدیته و طعم، معنی‌دار بود(05/0p<).  افزایش سرعت عبور هوا و ضخامت محصول موجب شد که زمان خشک شدن، زردی محصول (عاملb رنگ)، و کپک و مخمر افزایش اما روشنی (عاملL رنگ)، قرمزی (عامل  aرنگ)، و ویتأمین ث، کاهش یابد.  همچنین مشخص شد که محصول تولید شده در روش خورشیدی کیفیت بالاتری نسبت به محصول تولید شده در روش آفتابی دارد.  ضخامت 6/0 سانتی‌متر و سرعت جریان هوای 3متر‌بر‌ثانیه در خشک‌کن خورشیدی بهترین کیفیت و کمترین زمان خشک شدن را نشان دادند.  زمان خشک شدن نمونه‌ها در این شرایط نسبت به زمان خشک شدن در روش آفتابی 85 درصد کاهش یافت.

عنوان مقاله [English]

Optimum Conditions for Drying Pomegranate Arils in a Solar Dryer Using Surface Response Method

چکیده [English]

This study determined optimum conditions for drying pomegranate arils in a solar dryer. A cabinet solar dryer was used in active and mixed modes. The response surface method was employed with nine treatments (runs) and a control run (3 m/s air velocity and 2 cm in thickness) and five replications. The Bryte cultivar was tested and samples were dried to approximately 10% moisture. Drying time, vitamin C, color, acidity, and microorganisms were evaluated in the samples. The effects of thickness and air velocity on drying time and all qualitative factors were significant except for acidity and taste (p < 0.05). Drying time, yellowness (b factor in color) and microorganisms increased as thickness and air velocity increased. Brightness (L factor in color), redness (a factor in color), and vitamin C decreased with as thickness and air velocity increased. The quality of the dried products in the solar dryer was much better compared to the sun-dried control samples. Samples 0.6 cm in thickness with 3 m/s air velocity had the best quality in the solar dryer. Their drying time decreased 85% in comparison with sun drying.

کلیدواژه‌ها [English]

  • Pomegranate seeds
  • Response surface method
  • solar dryer
  • Sun drying
Anon. 1991. Fruit juices – Test methods. Institute of Standards and Industrial Research of Iran. ISIRI. No. 2685. (in Farsi)
Anon. 1993. Engineering research and design unit of producing and industrial karino company. Drying agricultural products a way to economic independence. (in Farsi)
Anon. 1998. Report of investigating pomegranate issues in Iran (Seminar). University Jehad. Agricultural and Natural Resources Collages from Tehran University Karaj. (in Farsi)
Anon. 1998. Microbiology of food and animal feeding stuffs - Horizontal method for the enumeration of yeasts and moulds - Part 1 : Colony count technique in products with water activity greater than 0.95. Iran National Standard. (in Farsi)
Anon. 2001. Dried pomegranate seeds (Anardane). Properties and experimental methods. Iran National Standard. (in Farsi)
Anon. 2006. Canned pickled cucumbers -Specifications and test methods. Iran National Standard. (in Farsi).
Anon. 2006. Microbiology of food and animal feeding stuffs - Horizontal method for the enumeration of microorganisms –Colony count technique at 30 c. 5272-1. Iran National Standard. (in Farsi)
Anon. 2008-2010. The result of a sample survey design for horticultural products. Ministry of Agricultural Jehad. Tehran. Iran. (in Farsi)
Akwasi, A. 1997. Dehydration of food crops using a solar dryer with convective heat flow. Solar Energy, 59 (4-6): 121-126.
Bchir, B., Besbes, S., Karoui, R., Attia,  H., Paquot,  M. and Blecker, C. 2010. Effect of air-drying conditions on physico-chemical properties of osmotically pre-treated pomegranate seeds. Food Bioprocess Technol. DOI 10.1007/s11947-010-0469-3.
Bennamoun, L. and Belhamri, A. 2002. Design and simulation of a solar dryer for agriculture products. J. Food Eng. 59, 259-266.
Dadashzade, M., Zomorodian, A. and Mesbahi, GH. 2008. The effects of air velocity and mode of drying on the moisture reduction trend in a cabinet solar drier. Research–Scientific J. Agric. Sci. Industry. 22, 23-43. (in Farsi)
Franz, R., Marcus, N., Hermann. L., Serm, J. and Busarakorn, M. 2009. Potential of roof-integrated solar collectors for preheating air at drying facilities in Northern Thailand. Renewable Energy. 34, 1661-1667.
Fuller, R.J. 1995. A comparison between solar dryers and convectional fuel dehydrators for on-farm drying. Drying Technol. 13(5-7): 1489-1502.
Gallali, Y.M., Abujnah, Y.S. and Bannani, F.K. 2000. Preservation of fruits and vegetables using solar drier: a comparative study of natural and solar drying.Chemical analysis and sensory evaluation data of the dried samples (grapes, figs, tomatoes and onions). Renewable Energy. 19, 203-212.
Horwitz, W. 2000. AOAC, Official methods of analysis of the association of official analytical chemists. 17 th ed. Association Official Analytical Chemists Washington. D.C. 2, 16-20.
Hyoung, S.L. and Chin, S.C. 1998. Rates of vitamin C loss and discoloration in clear orange juice concentrate during storage at temperatures of 4-24 °C. J. Agric. Food Chem. 46, 4723-4727. DOI: 10.1021/jf980248w.
Jairaj, K.S., Singh, S.P. and Srikant, K. 2009. A review of solar dryers developed for grape drying. Solar Energy. In press.
Janjai, S., Lamlert, N., Intawee, P., Mahayothee, B. and Bala, B.K. 2009. Experimental and simulated performance of a PV-ventilated solar greenhouse dryer for drying of peeled longan and banana. Solar Energy. In press.
Jokar, A., Maftoonazad, N. and jouker, L. 2011. Investigation of drying of pomegranate seeds by a tunnel dryer and sun drying. Research Report. Agric. Eng. Res. Ins. (AERI). Karaj. (in Farsi)
Kalra, S.K. and K.C., Bhardwaj. 1981. Use of simple solar dehydrator for drying fruit and vegetable products. J. Food Sci. Technol. (India). 18, 23-26.
Karabulut, I., Topcu, A., Duran, A., Turan, S. and Ozturk, B. 2007. Effect of hot air drying and sun drying on color values and β-carotene content of apricot (Prunus armenica L.). LWT - Food Sci. Technol. 40, 753-758.
Kingsly, A.R.P. and Singh, D.B. 2007. Drying kinetics of pomegranate arils. J. Food Eng. 79, 741-744.
Laing, B.M., Schlueter, D.L. and Labuza, T.P. 1978. Degradation kinetics of ascorbic acid at high temperature and water activity. J. Food Sci. 43, 1440-1443.
Mani, A. 1980. Hand book of solar radiation data for India. Madres. Allied Pub.
Mesbahi, GH., Zomorodian, A., Dadashzade, M. and Farahnaki, A. 2006. Comparison raisin production by solar drying and other methods. Iran Food Sci. Technol. J. 2, 61-73. (in Farsi)
Ndawula, J., Kabasa, J.D. and Byaruhanga, Y.B. 2004. Alterations in fruit and vegetable β-carotene and vitamin C content caused by open-sun drying, visqueen-covered and polyethylene-covered solar-dryers. African Health Sci. 4, 125-130.
Patil, R.T. 1984. Design and development of solar copla dryers. Agricultural Mechanization, Asia, Africa, Latin America. 15(2): 59-62.
Robertson, G.L. and Samaniego-Esguerra, C.M. 1990. Effect of soluble solids and temperature on ascorbic acid degradation in lemon juice stored in glass bottles. J. Food Quality. 13, 361-374. DIO: 10.1111/j.1745-4557.1990.tb00032x.
Sethi, V.P. and Sadhna, A. 2009. Improvement in greenhouse solar drying using inclined north wall reflection. Solar Energy. In press.
Shuzheng, F., Zhengfu, W., Xiaosong, H. and Ashim, K.D. 2009. Hot-air drying of whole fruit Chinese jujube (Zizyphus jujuba Miller): physicochemical properties of dried products. Inter. J. Food Sci. Technol. 44, 1415-1421.
Vidhan, J., Ara, D. and John, R.P. 2010. Anthocyanins and polyphenol oxidase from dried arils of pomegranate (Punica granatum L.). Food Chem. 118, 11-16.
Watts, B.M., Ylimaki, G.L., Jeffery, L.E. and Elias L.G. 1989. Basic Sensory Methods for Food Evaluation. The International Development Research Center Ottawa, ISBN, Canada. pp. 66-75.
Yaldyz, O. and Ertekyn, C. 2001. Thin layer solar drying of some vegetables. Drying Technology, 19 (3/4): 583-597.
Zare, D., Zomorodian, A. and Ghasemkhani, H. 2005. The effects of air velocity and time on the moisture reduction trend in a semi-continuous solar dryer. J. Sci. Technol. Agric. Nat. Res. 9, 264-251. (in Farsi)
Zomorodian, A. and Alame, A.R. 2002. Investigating drying rice in thin layer and determining the best thickness by applying a natural solar dryer. J. Sci. Technol. Agric. Nat. Res. 6, 217-209. (in Farsi)