Estimation of Moisture Loss From the Cooling Data of Potatoes

Abstract

A procedure was developed to predict moisture loss from cooling data of potato packed in gunny bags and stacked on wooden platforms in commercial cold stores. To predict the moisture loss, mass transfer coefficients k c and k m were estimated during the storage period, which were found to decrease with time. The calculated time average k c and k m values were 1.83 ¥ 10 -4 m/s and 2.31 ¥ 10 -10 kg/s·m 2 ·Pa during the transient cooling period and 1.59 ¥ 10 -4 m/s and 2.27 ¥ 10 -10 kg/s·m 2 ·Pa for the rest of the storage period, respectively. The estimated moisture losses were 4.8, 4.74 and 4.78%, at the center of three different stacks, for a storage period of 8 months. The corresponding experimentally measured weight losses at the center of the same stacks were 5.2, 5.1 and 5.26% with a variation of 11, 7.5 and 10.2%, respectively. Therefore, the procedure adopted in this study may be used to assess the moisture loss from potatoes under the different storage conditions. The effect of relative humidity (RH) and potato temperature on moisture loss was also predicted using the developed procedure. Decrease in RH of the storage air increased the moisture loss. The potatoes stored below 85% RH incurred more than 7% water loss. Therefore, 88-90% RH in the cold store may be used to limit the maximum moisture loss within the permissible limit of 5% even after 8 months of storage. It was also found that increasing the potato temperature exponentially increased the rate of moisture loss. 3 Corresponding Journal of Food Process Engineering 28 (2005) 397-416. All Rights Reserved. © Copyright 2005, Blackwell Publishing 397 398 M.K. CHOURASIA ET AL.

CFD simulation of effects of operating parameters and product on heat transfer and moisture loss in the stack of bagged potatoes

“…In the regime of natural convection in porous media, van der Sman (1999) pointed out that the air temperature can be taken equal to the product temperature, i.e., T f = T p = T; and the heat transfer can be described by a single energy equation eliminating the need for additional heat transfer equation on product-air interface. Chourasia, Maji, Baskey, and Goswami (2005) also confirmed the above hypothesis experimentally and articulated that at any particular instant of time, the temperature difference between the product and air in the stack does not vary significantly. Hence, single energy equation was chosen for the present case to describe the heat transfer in the stack of potatoes (Beukema, Bruin, & Schenk, 1983).…”

“…where Y i is mass fraction of species 'i', S i is species source term, kg m À3 s À1 and was obtained from (Chourasia et al, 2005)…”

Transpiration rate and quality of pomegranate arils as affected by storage conditions

“…As little as a 3 to 10% loss in weight could have an adverse effect on the appearance, saleable weight, texture quality of fresh and FC produce (Ben-Yehoshua, 1987). In a related report, when RH of storage air for potatoes was decreased below 85%, more than 7% water loss was observed (Chourasia et al, 2005). Similarly, an increase in water loss during the ripe phase of ''Hass'' avocados was observed when the fruits where transferred from RH of 90 to 20%, Burdon et al (2005) reported a 30% increase in moisture loss when RH of stored apples was reduced from 97.5 to 95%.…”

“…Fresh produce such as fruit release large amounts of water vapour and without appropriate packaging, water vapour could build-up inside the package, facilitating the growth of microorganisms (Mahajan, Oliveira, & Macedo, 2008). Transpiration rate (TR) of produce during postharvest handling and storage is influenced by intrinsic factors such as surface-to-volume ratio, surface injuries, morphological and anatomical characteristics, as well as maturity stage (Sastry & Buffington, 1982), and extrinsic factors such as temperature, RH, air movement, and atmospheric pressure (Chourasia, Maji, Baskey, & Goswami, 2005). Pomegranate (Punica granatum L.) has been well documented for its potential health benefits such as its high antioxidant, anti-mutagenic, anti-hypertension, anti-inflammatory and anti-atherosclerotic activity against osteoarthritis, prostate cancer, heart disease and HIV-1 (Rı´os-Romero et al, 2012;Viuda-Martos, Ferna´ndez-Lo´pez, & Pe´rez-Á lvarez, 2010).…”

Product‐cooling Load and Moisture Loss Under Different Loading Patterns and Cooling Rates of Potatoes in Cold Storage

“…The loss of moisture from the potato surface removes the latent heat of evaporation and produces the cooling effect. The rate of loss of moisture from the potato was calculated based on the procedure suggested by Chourasia et al . (2005):…”