Document Type : Original Article

Author

Assistant professor, Department of Food Science and Technology, Quchan Branch, Islamic Azad University, Quchan, Iran.

Abstract

Saffron is the most valuable spice known in the world. Crocin, picrocrocin and safranal are known as saffron color, taste and aroma indices, respectively. Drying is one of the most important steps affecting the final quality of saffron in terms of crocin, picrocrocin and safranal content. In this study, the efficiency of drying process by oven method based on important variables such as temperature, time and thickness of saffron layer was modeled by artificial neural network method. Modeling results of saffron drying process by oven method showed that if crocin changes under momentum learning rule and tangent transfer function with 8 neurons and 25, 55 and 20% of the data were used for evaluation and test training respectively; the coefficient has the highest correlation coefficient (0.914). Whereas for the changes of picrocrocin, the Levenberg learning law and the tangent transfer function in the number of neurons, 12 designed the best networks with 50, 25 and 25% of data for training, evaluation and testing, respectively (R = 0.986). Safranal changes were also predicted by the Levenberg learning law and Sigmoid transfer function in neuron number 8 with 35, 45 and 20% of the data for training, evaluation and testing with appropriate correlation coefficient of 0.981 and predicted by its network.

Keywords

Atefi, M., Akbari Oghaz, A.R., and Mehri, A., 2013. Drying effects on chemical and sensorial characteristics of saffron. Iran. J. Nutrition Sci. & Food Technol. 8(3), 201-208. [in Persian with English Summary].
Bansi, L., Raina, S.G., Agarwal, B., Ashok, K., Bhatia, I., and Govind, S.G., 1996. Changes in pigments and volatiles of saffron (Crocus sativus L.) during processing and storage. J. Sci. Food Agric. 71, 27-32.
Delgerange, N., Cabassud, C., Cabassud, M., Durand-Bourlier, L., and Lain, J.M., 1998. Neural network for prediction of ultrafiltration transmembrane pressure application to drink water. J. Membr. Sci. 150, 111–123.
Delshad, S., and Hakimzadeh, V., 2017. Optimization of saffron drying parameters by using oven and microwave using response surface methodology. J. Saffron Res. 5(2), 151-162. [in Persian with English Summary].
Gregory, M.J., Menary, R.C., and Davies, N.W., 2005. Effect of drying temperature and air flow on the production and retention of secondary metabolites in saffron. J. Agric. Food Chem. 53, 5969–5975.
ISIRI., 2001. General Saffron Specification. No. 259, Institute of Standards and Industrial Research of Iran. [in Persian].
ISO-3632-2-2003., 2003. Part I: Specification, Part 2: Test Methods. International Organization for Standardization, Geneva.
Madan, C., Kapur, B., and Gupta, U., 1966. Saffron. Econ. Bot. 20(4), 377-85.
Akhondi, E., Kazemi, A., and Maghsoodi, V., 2012. Determination of a suitable thin layer drying curve model for saffron (Crocus sativus L.) stigmas in an infrared dryer. Sci. Iran. 18(6), 1397–1401. [in Persian with English Summary].
Mazloumi, M., Taslimi, A., Jamshidi, A., Atefi, M., Haj Seyed Javadi, N., Komeyli Fanood, R., Seyed Ahmadian, F., Falahat Pishe, H., Choobdar, N., Hadian, Z., Golestan, B., and Shafighi, A., 2007. Comparing the effects of drying methods using by vacuum, freezing, sun, microwave with traditional method on properties of Ghaen saffron. Iran. J. Nutr. Sci. & Food Technol. 2(1), 69-76. [in Persian with English Summary].
Melynk, J.P., Wang, S., and Marcone, M.F., 2010. Chemical and biological properties of the world’s most expensive spice: Saffron. Food Res. Int. 43, 1981-1989.
Movagharnejad, K., and Nikzad, M., 2007.Modeling of tomato drying using artificial neural network. Comp. Elect. P. 78-85.
Rios, J., Recio, M., Giner, R., and Manez, S., 1996. An update review of saffron and its active constituents. Phytother. Res. 10(3), 189-93.
Razavi, S.M.A., Mousavi, S.M., and Mortazavi, S.A., 2003. Dynamic prediction of milk ultrafiltration performance: A neural network approach. Chem. Eng. Sci. 58, 4185–4195.
Salehi, F., and Razavi, S.M.A., 2012. Dynamic modeling of flux and total hydraulic resistance in nano filtration treatment of regeneration waste brine using artificial neural network. Desalin. Water Treat. 41, 95-104.
Shahidi Noghabi, M., Razavi, S.M.A, and Mousavi, S.M., 2012. Prediction of permeate flux and ionic compounds rejection of sugar beet press water nanofiltration using artificial neural networks. Desalin. Water Treat. 44(1–3), 83–91.
Shahriari. S., Hakimzadeh, V., and Shahidi, M., 2017. Modeling the efficiency of microfiltration process in Reducing the hardness, improvement the non-sugar component rejection and purity of raw sugar beet juice. Ukr. Food J. (6)4, 648-660.
Sujata, V., Ravishankar, G., and Venkataraman, L., 1992. Methods for the analysis of the saffron metabolites crocin, crocetins, Picrocrocin and safranal for the determination of the quality of the spice using thinlayer chromatography, high-performance liquid chromatography and gas chromatography. J. Chromatogr. A. 624(1), 497-502.
Trantilis, A.P., Beljebbar, A., Manfair, M., and Polissou, M.F.T., 1998. Raman spectroscopic study of carotenoids from saffron (Crocus sativus L.) and some derivatives. Spectroch. Acta. 54, 651-657.
Winterhalter, P., and Straubinger, M., 2000. Saffron-renewed interest in an ancient spice. Food Rev. Int. 16(1), 39-59.