NONGLAM UNIVERSITY
FACULTY OF FOOD SCIENCE AND TECHNOLOGY
196596031877000
RESEARCH PROPOSAL
Development processing dried watermelon rind with Stevia sweetener
Student name:Le Thi Hong Cam (Julia)
ID: 15125327
Email: [email protected]
Jun, 2019
RESEARCH PROPOSAL
Development processing dried watermelon rind with Stevia sweetener
INTRODUCTION
Watermelon is a tropical fruit tropical fruit widely consumed around the world and particularly among Vietnamese. The biggest area produced watermelon in the world is Asia. According to Food and Agriculture Organization statistics (FAO,2017), the production in this area is 99,1 million tons, accounting for 83,7% of the world watermelon production.
Watermelon has high levels of antioxidants such as lycopene and vitamin C, high in fiber, so much water and so it is considered a nutritious fruit.
In recent times, there have been challenges in agro-wastes management due to yearly increase in production in perishable fruits which does not commensurate with consumer utilization. Hence more wholesome fruit are discarded indiscriminately in the environment. This development makes reuse and value addition of agro-waste a viable methodology capable of reducing their environmental impact.
Watermelon rind is one of the major solid wastes generated by several restaurants, cottage fruit juice producers and food industries. The utilization of watermelon rind will reduce the amount of the waste discarded, create more income for farmers, food processors and more importantly reduce environmental impacts of the waste.
Nowadays, modern consumers have an increase concerned with the nutritional and caloric value of foods they consume, looking for healthier, innovative, safe, and easy to use products. Thus, an increase in the consumption of diet and light products has been observed, suitable for restrictive caloric diets and healthier eating habits. Consumption of excessive quantities of sucrose increases the energy intake which can lead to harmful effects on the body, including obesity and chronic diseases. Hence, the products suitable for diabetics should be formulated with sucrose substitutes by sweeteners such as sorbitol, maltitol, sucralose, stevioside, etc. Stevioside provides zero calories in a wide range of beverages and foods and well-suited for blending with other non-calorie or carbohydrate sweeteners. The stevioside is stable under dry conditions and its stability is significantly better than other artificial sweeteners like aspartame.
In view of all these issues, the main focus of this research is to successfully document the physicochemical properties and sensory characteristics of dried fruit product made from watermelon rind. Investigation the formulation of dried watermelon rind uses Stevia, as an alternative sweetener, with or without added sucrose.
OBJECTIVES
The purpose of this research is to investigate a possible formulation of dried watermelon rind using Stevia, as an alternative sweetener, with or without sucrose and examine the products physico chemical and sensory properties.
Research contents include:
To determine specifications and chemical compositions of raw watermelon rind.
Investigation affects of sucrose and sweetener ratio in osmotic solution on sensory evaluation.
To determine effects of temperature on time and sensory evaluation of product.
Suggestion processing of dried watermelon rind.
MATERIALS:
Watermelon rind
Refine sugar
Stevia extract
METHODOLOGY
Flow diagram
Green layer
Experiment 1: To determine specifications and chemical compositions of raw watermelon rind.
Experiment 2: Investigation affects of sucrose and sweetener ratio on sensory evaluation.
Experiment 3: Determination affects of temperature on time and sensory evaluation of product affecting sensory evaluation.
Immersing in osmotic solution
Rinsing
(40 50oC)
Drying
Packing
Product
Washing
Slicing
Blanching
(80oC 90oC, 1-2 mins)
Watermelon rinds
Removing outer skin
Green layer
Experiment 1: To determine specifications and chemical compositions of raw watermelon rind.
Experiment 2: Investigation affects of sucrose and sweetener ratio on sensory evaluation.
Experiment 3: Determination affects of temperature on time and sensory evaluation of product affecting sensory evaluation.
Immersing in osmotic solution
Rinsing
(40 50oC)
Drying
Packing
Product
Washing
Slicing
Blanching
(80oC 90oC, 1-2 mins)
Watermelon rinds
Removing outer skin
Figure SEQ Figure * ARABIC 1 Flow diagram of dried watermelon rind processing
Process explanation
The watermelons (C. lanatus) are purchased from market. The watermelons are washed thoroughly and peeled. Only the rinds are used to develop the dried fruit while the flesh is discarded. The green layers of the rinds are removed, and the remaining white flesh is cut into 0,6 0,8 mm thick pieces. Then the rinds are blanched in water at 80 90oC for 1 min, taken out and drained. After that, the samples submerge in osmotic solution which slowly impregnated the rind tissues with sugar until the sugar concentration is high enough to prevent microbial spoilage.
After the process of sugars impregnation, the samples are taken and washed with warm water (40 50oC) and then drained, to eliminate the excess of solution from the surface.
The drying process aims to reduce the moisture content in the rinds to 20%, which can prolong the preservation time for the product. The product is cooled and packaged in high density polyethylene bags for process evaluation.
Experimental design
Experiment 1: Determination of specifications and chemical compositions of raw watermelon rind.
Determination of the content of moisture content, ash content: The moisture content was determined using the air oven method (AOAC, 2000)
Determination of total soluble solid by refractometer
Determination acidity by titration with NaOH 0,1N.
Determination vitamin C and total sugar.
Experiment 2: Investigation affects of sucrose and sweetener ratio on sensory evaluation.
The aim: to choose the suitable ratio of sucrose and Stevia which supplied in osmotic solution.
Experiment design: the experiment is randomized designed with one factor, 5 treatments and 3 replications.
Factor: the ratio of sucrose and stevia is supplied in osmotic solution including 5 levels of content: 100% sucrose; 75% sucrose + 25% stevia; 50% sucrose + 50% stevia; 25% sucrose +75% stevia; 100% stevia.
The quality measurement:
Measuring physico chemical compositions of samples.
Measuring the color of dried products.
Sensory evaluation about color, aroma, taste, texture
Experiment 3: Determination affects of temperature on time and sensory evaluation of product affecting sensory evaluation.
The aim: Determination suitable drying condition for dried watermelon rind.
Experimental design: Experiment is designed 1 factor with 3 treatments and 3 replications.
Factor: The temperature of dryer at 55oC, 60oC, 65oC.
The quality measurement:
Evaluate sensory about color, aroma, taste and texture of products.
Evaluation sensory
Dried watermelon is evaluated organoleptically for color, flavor, texture and overall acceptability. All samples are served and coded with three digits chosen at random. All panelists evaluate the samples using a 9-point category hedonic scale from 1= extremely dislike to 9= extremely like.