with the collaboration of Iranian Food Science and Technology Association (IFSTA)

Document Type : Research Article

Authors

1 Department of Chemical Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran.

2 Agricultural Engineering Research Department, Fars Agricultural and Natural Resources Research and Education Center, Agricultural Research, Education and Extension Organization (AREEO), Shiraz, Fars, Iran.

3 Agricultural Engineering Research Institute (AERI), Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran.

Abstract

Introduction: The date palm (Phoenix dactylifera), is one of the most important plants of arid desert area of the western and southern Asia and northern Africa for over 5000 years. Date fruit has a great importance in nutrition due to being a main source of carbohydrates, but it is low in fat and protein. Also it is a good source of many minerals and high amounts of antioxidants which prevent some diseases. This fruits is an important element in economy of date growing countries. Some factors such as variety, environmental impact of growing regions and large quantities of the produced date causes postharvest losses resulting in lower quality fruits. These amounts of fruit which are not consumed directly as fresh may have been used as raw materials to formulate some products like date syrup, powder, jam, etc. Date powder is a highly nutritional quality sweetener obtained from date for sucrose substitution in confectionary, bakery or ice cream industry. Stickiness is a problem in production of fruit powder during drying, transportation and storage. Stickiness in fruit powder is mainly due to the presence of low molecular weight sugar such as fructose, glucose, sucrose and organic acids in fruits. These compounds are very hygroscopic in the amorphous state and have low glass transition temperature and leads to increase stickiness and decrease stability of the product in room temperature. This research consisted of two major objectives: i) determination of an optimum proportion of date paste, silicon dioxide and maltodextrin and the most suitable temperature of drying; ii) characterization of physicochemical and thermal characteristics of date powder.

Materials and methods: Kabkab date was purchased from local market of Kazeroun, Fars, Iran. Moisture, ash, protein, fat, total sugar and dietary fiber contents were determined by AOAC methods (AOAC, 1997). Date flesh was minced by a kitchen meat grinder to make a smooth paste. Three different proportions of maltodextrin (35, 45 and 55% w/w) and three proportions of silicon dioxide (0, 0.75 and 1.5% w/w) were added to date paste to produce date powders. The mix was then spread to a thickness of about 5 mm on a Teflon coated tray and kept inside an oven dryer at 50, 60 and 70°C. The dry product was then ground in a hammer mill to produce date powder. The powder was immediately collected in plastic pouches and kept in desiccators to avoid moisture absorption from the air. Laboratory test sieves were used to collect date powder with particle size less than 1mm in diameter. Some physical and thermal characteristics of the powders were measured. Response surface methodology with central composite design was applied to minimize total number of experimental runs and to optimize the proportions of maltodextrin and silicon dioxide and also drying temperature. The dependent variables were density, moisture and color parameters. A completely randomized design was applied to analyze the effect of maltodextrin on thermal properties (glass transition temperature and specific heat) of date powder. Significant terms were found using ANOVA (P

Keywords

Abadio, F.D.B., Domingues, A.M., Borges, S.V., Oliveira, V.M. 2004.Physical properties of powdered Pineapple (Ananascomosus) juice: effect ofmaltodextrins concentration and atomization speed. Journal of Food Engineering, 74,285-287.
Agricultural Statistics. 2014. Ministry of Jihad-e-Agriculture, Deputy of Planning and Economics, Center for Information and Communication Technology, Vol. 3.
AOAC. 1990. Official methods of analysis of the AoAc. In: Harwich, K. (Ed.), Arlington: Association of official Analytical chemists.
Badii, F. 2012. Preparation of date powder from grade 2 fruit and study its physicochemical properties. Agricultural Engineering Research Institute. Karaj, Iran.
Behlau, L. and Widmann, G. 2008. Collection applications thermal analysis, food. Mettler Tolledo, 15-16.
Chao, C.H.A. and Kruger, R.R. 2007. The Date palm (phoenix dactyliferal.): Overview of Biology, uses, and cultivation, 42, (5), 1077-1078.
Chronakis, I.S., 1998. On the molecular characteristics, Compositional properties, and structural – functional mechanisms of maltodextrins: a review. Critical Review in Food science and Nutrition, 38(7), 599-637.
Dokic, L., Jakovljevicj, Dokic. P. 2004 Relation between Viscous characteristics and dextrose equivalent of multodextrins. Starch – Starke, 56 (11), 520 – 525.
FAOST data. 2010. http://faostat. FAO org/site/ 567//Desktop Default. Aspx? pageID= 56.
Farahnaky, A., Mansoori, N., Majzoobi, M. and Badii, F. 2016. Physicochemical and sorption isotherm propertiesof date syrup powder: Antiplasticizing effect ofmaltodextrin. Food and Bioproduct Processing, 98, 133-141.
Goula, A.M., Adamopoulos, K.G. 2010. A new technique for spray drying orangejuice concentrate. Innovative Food Scienceand Emerging Technologies 11, 342-351.
Grabowski, J.A., Truong, V.D., Daubert, C.R. 2006. Spray-drying of amylase hydrolyzed sweetpotato puree and physicochemical properties of powder.Journal of Food Science, 71, 209-217.
Jaya, S. and Das, M. 2004. Effect of maltodextrin, glycerol mono stearate and tricalcium phosphate on vacuum dried mango powder properties. Journal of Food Engineering, 63, 125-134.
Kha, T.C., Nguyen, M.H., Roach, P.D.2010. Effect of spray drying conditions on the physicochemical and antioxidant properties of Gac (Momordica cochinchinensis) fruit aril powder. Journal of Food Engineering, 98, 385-392.
Mishra, P., Mishra, S. and Mahanta, C. L. 2014. Effect of maltodextrin concentration and inlet temperature during spray drying on physicochemical and antioxidant properties of amla (Emblica officinalis) juice powder. Food and Bioproduct processing, 92(3), 252-258.
Myers, R. H., Montgomery, D. C. 1995. Response surface methodology, process and product optimization using designed experiment (2nd ed.). New York: John Wiley and Sons.
Park, K., Emy Kurozawa, L., Dupas Hubinger, M. 2009. Effect of maltodextrin and gum Arabic on water sorption and glass transition temperature of spray dried chicken meat hydrolyses protein, Journal of Food Engineering, 91, 287-295.
Quek, S.Y., Chok, N.K., Swedlund, P. 2007. The physicochemical properties of spray dried water melon powder. Chemical Engineering and Processing, 46, 386-392.
Rao, P.V.K. J., Das, M., Das, S.K. 2009. Changes in physical and thermo-physical properties of sugarcane, Palmyra-palm and date-palm juices at different concentration of sugar. Journal of Food Engineering, 90, 559–566.
Roos, Y. H. 1995. Glass transition – related – related physicochemical changes in foods. Food Technology, 97, 100- 102.
Sahari, M.A, Hamidi – Esfehani, Z., samadlui, M. 2008. Optimization of vacuum drying characteristics of date palm. Drying Technology, 26, 793-797.
Silva, M.A., Sobral, P.J.A., Kieckbusch, T.G., 2006. State diagrams offreeze-dried camucamu (Myrciaria dubia (HBK) Mc Vaugh) pulpwith and without maltodextrin addition. Journal of Food Engineering, 77,426–432.
Sablani, S. Shrestha, A. K., Bhandari, B. 2008. A new method of producing date powder granules: physicochemical characteristics of powder, 87, 416- 421.
Zheng, M., Jin, Z., Zhang, Y. 2007. Effect of cross – linking and esterification on Hygroscopicity and surface activity of cassava maltodextrins. Food chemistry, 103(4), 1375-1379.
CAPTCHA Image