Agricultural Research Management Information System

Home
Research Summary
Search
About Us
- ARMIS
- Brochure
Contact Us
Report
User Request
Data Input
Help
- Operation Manual
  - PDF
  - Video
- Program Area & Commodity
We have reached 37600 number of research entries at this moment.

- Logout

Research Detail

Home
Research
Detail

Effect of Starch Edible Coating on Drying Characteristics and Antioxidant Properties of Papaya

M. Z. Islam
Department of Food Engineering and Tea Technology, Shahjalal University of Science and Technology, Sylhet 3114, Bangladesh

Turzo Saha ·
Department of Food Engineering and Tea Technology, Shahjalal University of Science and Technology, Sylhet 3114, Bangladesh

Abstract/ Executive Summary:

The aim of the study was to investigate the effect of potato starch coating on the drying efciency and quality of papaya. The potato starch with diferent concentration of 1%, 2% and 3% and calcium gluconate salt of 0.5% w/w were applied as an edible coating before drying. The efect of coating on the retention of bioactive compounds and physical properties of papaya during hot air drying at various temperature of 50 °C, 60 °C and 70 °C were investigated. The rehydration ratio and shrinkage percentage of the edible coated dried papaya slices were reduced whereas the moisture content, water activity and hardness were increased with the increasing of the concentration of edible coating. The edible coating retains the color loss during drying. The drying behavior of all the coated samples was best described by Midilli-Kucuk model, whereas the control samples followed the Page model with higher R2 and lower RMSE values. The retention percentage of antioxidants were increased by increasing the concentration of the potato starch coating, but the higher air-drying temperature reduced the antioxidants signifcantly (p≤0.05).

Keywords: Papaya · Potato starch · Edible coating · Drying models · Physical properties · Antioxidants

Location: Local market in Sylhet Bangladesh

Start Date: 00-00-2017

End Date:

Program Area: Resource Development and Management

Commodity: Papaya

Objectives:

The study is carried out (i) to determine the drying characteristics of edible coated and uncoated papaya slices (ii) to determine the effects of edible coating on the physical and antioxidant properties of papaya slices.

Methodology:

Sample preparation The papaya fruits (Carica papaya L.) of oval shape with good physical conditions were randomly collected from at least 3 diferent trees to yield a representative sample. About 30 kg of papaya fruits were collected in the summer of 2017 from the local market in Sylhet Bangladesh. The average weight of each papaya was about 800 g–1.0 kg, with the maturity state of 50–60% epicarp yellow, moisture content 89.5% fresh weight, Brix of 10.5 and pH 4.52. The fruits were then cut (remove the seeds and peel) longitudinal direction with the dimensions of 20 mm×20 mm×5 mm. Each batch about 250 g of triplicate samples was taken as a representative sample. Then immediately coating was done. Edible coating The edible coating was prepared using aqueous solutions having 1%, 2% and 3% of potato starch and 0.5% w/w of calcium gluconate salt. The edible coating formulations were obtained by heating the aqueous solution at 70 °C under constant agitation up to gel formation. After this procedure, the solution was kept at room temperature for cooling. Each batch about 250 g of triplicate samples was taken to coating. Then the papaya slices were immersed in the solutions for 1 min with a perforated basket. After that samples were taken out and dried at room temperature for 15 min to fx the coating. Drying experiment After pretreatment, the convection drying of coated papaya slices was performed by using the Hot Air-dryer (ModelOF-21E, Korea). The drying temperature was maintained at 50 °C, 60 °C and 70 °C and during drying with a constant humidity of 50% and 1.5 m/s air fow rate was also maintained. For achieving the steady-state conditions, the dryer was adjusted to be the selected temperature for about half an hour before starting the drying operation. Each batch about 250 g of triplicate samples was taken to dry. The weight loss of the samples was recorded every 30 min interval until 2 h and after 2 h weight loss measurement was recorded at 1 h intervals for total 6 h. The experiments were repeated for three times to estimate the moisture ratio and drying rate. Mathematical modeling The moisture contents of papaya slices were determined by drying in an oven at 105 °C until consecutive constant mass were obtained, followed by 2 h intervals and which gave variation less than 0.3%. Moisture content expressed as kg water/kg of dry matter. The moisture content at any time (kg water/kg of dry matter), Mt was calculated.

Source of Information: Journal of Food Measurement and Characterization

Article Link (Online Journal): https://doi.org/10.1007/s11694-019-00215-3

Funding Source:

Budget:

Total Budget (Tk.) :

Achievement/Findings:

Papaya (Carica papaya L.) due to its perishable nature, subjected to a huge quantity of loss every year. The purpose of this study was to evaluate the combined efect of a calcium salt with potato starch an as edible coating before drying to preserve the more functional and nutritional quality of the papaya slices. The physical properties like water activity greatly reduced of all the papaya slices during drying. It will help to preserve the slices for a long time without microbial damage. The calcium salt with potato starch coating retained the maximum color intensity as chroma values and lower color diference than the uncoated sample. The drying characteristics of all the papaya slices were evaluated with four thin layer drying models such as Exponential model, Page model, Midilli-Kucuk and Logarithmic model. The experimental dimensionless moisture ratio vs drying time curve was plotted and each model was evaluated based on the R2 and RMSE values. All models can describe the experimental data, among them Page model and Midilli-Kucuk model best described the control and coated samples at various drying conditions respectively. The edible coating reduced the thermal losses of the bioactive compounds of all the samples during drying. Further study is needed to evaluate the shelflife and sensory quality of the papaya slices.

Knowledge Management: Journal