Zainal Samicho

Effect of maturity of pineapple variety N36 on its waste physico-chemical properties

Normally pineapple index 2 are harvesting for canning process. Pineapple waste is a by-product from the pineapple canning processing that will lead to serious environmental pollution. Some of pineapple waste is used for animal feed but it is still under utilized. Pineapple waste contains valuable nutrient component of simple sugar such as sucrose, glucose and fructose. Analysis of physico-chemical properties is an important data for determination achievable basic requirement to produce beverage or to run other process such as alcoholic and acetic acid fermentations for producing vinegar. The aim of this study is to determine the effect of maturity of pineapple variety N36 on its waste physico-chemical properties. The selected pineapple wastes such as peel, crown and core were used to produce pineapple waste extracts. Significant difference at p<0.05 found between total soluble solid (TSS), pulp, absorbance, pH, titratable acidity and TSS/TA ratio among index of maturity. It was found that pineapple core extract contains significantly highest in fructose, glucose and sucrose compared to pineapple crown and peel extracts.

Optimization of thermal processing condition for winter melon puree using response surface methodology

Winter melon is a perishable fruit, hence, the need to process it into puree is a necessity. The concept of thermal processing involves in canning process as the most widely used method of preserving and extending the shelf life and capable to inactivate pectinmethylesterase enzyme (PME) in fruit puree was studied. The purposes of this study are to determine the optimum temperature and time for thermal processing of winter melon puree (WMP) and to verify the optimum condition proposed by response surface methodology (RSM). Winter melon puree samples was treated at thirteen different treatment combinations of temperature (°C) and time (second). Each treatment of WMP was analysed for the percentage (%) reduction of PME, total phenolic content (TPC), percent pulp content and physicochemical analysis such as colour (absorbance), total soluble solid (°Brix) and pH. PME and TPC were the responses used in this research. For each treatment % reduction of PME ranged from 27.61–78.05 % while TPC ranged from 12.21–28.84 mg GAE/g fresh weight. The % of pulp content for each treatment of WMP varies from 51.17–63.17 %. However, there were no significance difference results in the colour, total soluble solid and pH of WMP samples. The MINITAB software version 15 used for optimization suggested three possible optimum conditions but the best desirability where the experiment was feasible at temperature 84.5 °C and time 94.1 seconds. At this optimum treatment, the predicted value of % reduction of PME was 78.87 % and TPC 20.34 mg GAE/g fresh weight. After verification at the optimum treatment, results showed that % reduction of PME was 78.12 % and TPC was 20.43 mg GAE/g fresh weight and since the difference values between predicted and verification for both responses (PME and TPC) are less than 5% meaning that the optimum condition predicted by RSM of MINITAB software version 15 can be accepted at the 5% level of significant difference. At this condition pH of WMP was 4.76, colour absorbance 0.4124 nm, % pulp content 55.0 % and total soluble solid 1.282° Brix. All derived mathematical model for the response was found fit significantly to predict the data. This study showed that RSM does not only reduce the number of experiment to be carried out but also effective tool in determining the optimum condition of thermal treatment for WMP.

Rheological properties of N36 pineapple waste for different stages of maturity

Rheological properties of pineapple waste extract (peel, crown and core) for different maturity indices were studied at room temperature (25°C). The MCR300 rheometer with measuring system concentric cylinder (CC27) was used to determine the rheological properties of pineapple waste extracts. Besides, the physical properties of pineapple waste extracts such as pulp, total soluble solid contents and density were also determined. The results show that pineapple peel, crown and core extract behaved pseudoplastic characteristic and were influenced by maturity index of pineapple and physical properties of pineapple waste extract.

Extraction of chitosan & its film-forming properties: A review

Chitosan is a naturally-occurring polysaccharide produced from deacetylation of chitin. It is abundant in exoskeletons of marine creatures. Among of its interesting characteristics is its ability to bind fat and cholesterol, antimicrobial, and anti-oxidation properties. Due to its anti-microbial and anti-oxidation properties, chitosan has been used as films coatings for vegetables and fruits. This paper presents a review of current research in chitosan extraction as well as methodology for synthesizing film casings with it.