Effect of radiation heat on the physical and chemical properties of bread incorporated with garcinia mangostana / Ummi Kalthum Ibrahim

Radiation is considered as the main process of heat transfer occurred in the oven during baking process. The sources of radiation energy are generated from heating elements as well as the oven surfaces. In this study, the effect of heat distribution due to the radiation energy inside the baking oven was analysed using network representation model. This model is developed by considering the configuration and the area of oven wall surfaces. Two types of oven were used (high and low emissivity) to evaluate the performance on radiation effect. The best oven performance condition was selected to be used in functional bread baking. In this work, Garcinia mangostana pericarp powder has been chosen to be incorporated in the bread due to the large amount of xanthones content in its pericarp. Xanthones has the ability as an antioxidant, antibacterial, anti-inflammatory and anticancer. The functional bread characteristics that being investigated were antioxidant activity, total phenolic content, surface colour and moisture content. The baking conditions were set at baking temperatures of 180°C, 200°C and 220°C while baking time was varied from 15 to 30 minutes and concentration of Garcinia mangostana pericarp powder varies from 0.5 wt% to 2 wt%. The experimental operating conditions were carried out systematically generated by Design Expert version 6.0. The colour development of bread crust and crumb was measured and expressed as L* (lightness), a* (redness) and b* (yellowness) values. The antioxidant activity and total phenolic content of bread samples were measured using DPPH (2,2-diphenyl-l-picrylhydrazyl) and Folin-Ciocalteu assays, respectively. The network model was successfully developed and was used to determine the radiation heat in baking oven. The results showed that high emissivity oven (black surface) provides more radiation heat compared to low emissivity oven (shiny surface). Therefore, high emissivity oven was used for baking bread incorporated with Garcinia mangostana pericarp powder. It was found that, incorporation of 0.5 wt% to 2 wt% of Garcinia mangostana pericarp powder in bread increased the antioxidant activity up to 90% of radical scavenging activity and total phenolic content up to 30 mg GAE/g. The surface colour and moisture content of the incorporated bread are also similar to the control sample. For optimisation process, it was found that baking temperature, baking time and concentration of pericarp powder give significant effect on total phenolic content. antioxidant activity, bread crust and crumb surface colour and moisture content. The optimum level of baking condition was found to be at baking temperature of 213°C, baking time of 23 minutes and Garcinia mangostana pericarp powder concentration of 0.87wt%

Effect of radiation heat on the physical and chemical properties of bread incorporated with garcinia mangostana / Ummi Kalthum Ibrahim

Radiation is considered as the main process of heat transfer occurred in the oven during baking process. The sources of radiation energy are generated from heating elements as well as the oven surfaces. In this study, the effect of heat distribution due to the radiation energy inside the baking oven was analysed using network representation model. This model is developed by considering the configuration and the area of oven wall surfaces. Two types of oven were used (high and low emissivity) to evaluate the performance on radiation effect. The best oven performance condition was selected to be used in functional bread baking. In this work, Garcinia mangostana pericarp powder has been chosen to be incorporated in the bread due to the large amount of xanthones content in its pericarp. Xanthones has the ability as an antioxidant, antibacterial, antiinflammatory and anticancer. The functional bread characteristics that being investigated were antioxidant activity, total phenolic content, surface colour and moisture content. The baking conditions were set at baking temperatures of 180°C, 200°C and 220°C while baking time was varied from 15 to 30 minutes and concentration of Garcinia mangostana pericarp powder varies from 0.5 wt% to 2 wt%. The experimental operating conditions were carried out systematically generated by Design Expert version 6.0. The colour development of bread crust and crumb was measured and expressed as L* (lightness), a* (redness) and b* (yellowness) values. The antioxidant activity and total phenolic content of bread samples were measured using DPPH (2,2-diphenyl-l-picrylhydrazyl) and Folin-Ciocalteu assays, respectively. The network model was successfully developed and was used to determine the radiation heat in baking oven. The results showed that high emissivity oven (black surface) provides more radiation heat compared to low emissivity oven (shiny surface). Therefore, high emissivity oven was used for baking bread incorporated with Garcinia mangostana pericarp powder. It was found that, incorporation of 0.5 wt% to 2 wt% of Garcinia mangostana pericarp powder in bread increased the antioxidant activity up to 90% of radical scavenging activity and total phenolic content up to 30 mg GAE/g. The surface colour and moisture content of the incorporated bread are also similar to the control sample. For optimisation process, it was found that baking temperature, baking time and concentration of pericarp powder give significant effect on total phenolic content, antioxidant activity, bread crust and crumb surf ace colour and moisture content. The optimum level of baking condition was found to be at baking temperature of 213°C, baking time of 23 minutes and Garcinia mangostana pericarp powder concentration of 0.87wt%

Antioxidant activity of fresh and dried extracted herbs mixture of Psidium guajava, Pteridophytes, Cymbopogon, and Pandanus amaryllifolius / Ummi Kalthum Ibrahim and Amirah Adniruddin

This study aims to investigate the effect of solvent concentration and extraction temperature on antioxidant activity of fresh and dried mixture of Psidium guajava, Pteridophytes, Cymbopogon, and Pandanus amaryllifolius. The samples were extracted using different concentration of methanol (0, 30, 50,and 70% (v/v)) in a shaking water bath at temperature of 60 °C and 90 °C for 30 minutes. From the results, the antioxidant activities were dependent on the solvent concentration and the temperature during extraction. The condition of both samples demonstrated different antioxidant activities. The highest antioxidant activities were found at 30% (v/v) methanol concentration and 60 °C indicating by the scavenging percentage of 53.85% and 65.93% for fresh and dried mixture, respectively. However, 70% (v/v) of methanol concentration exhibited the lowest antioxidant activities of fresh and dried mixture, showing 29.67% and 42.86%, respectively. Overall, the antioxidant activity in oven dried samples is higher than in the fresh samples. Other than that, GC-MS analysis presented the octen-1-ol,3,7-dimethyl (0.240%), cis-á terpineol (0.334%) and 6-octenal, 3,7-dimethyl (0.205%) as a major component in the extracts

Biodiesel production from waste cooking oil: a brief review

Biodiesel is a source of new renewable energies and a substitute fuel with much potential in the future for petroleum-derived diesel. According to BP Statistical Review of World Energy, total global consumption of diesel from petroleum increasing in one decade which is 3.5 million tonnes in 2010 and 3.9 million tonnes in 2019. Despite reducing the dependence on fossil fuel, the question of how waste cooking oil (WCO) disposal and related environmental damage issues might be solved by biodiesel production. In Malaysia, an estimated 540 000 tonnes of WCO from vegetable and animal fats are discarded each year without being treated as wastes. WCO recognize as a raw material for biodiesel process and have a great potential. Biodiesel is made through a reaction between triglyceride and alcohol, with triglyceride being a raw material found primarily in plants and animals. Transesterification is the popular process of biodiesel production with low cost and mild reactions conditions. Some studies have done on the variable of trans- esterification process with the optimum condition of biodiesel production from WCO. This study exam- ines WCO as a raw material for biodiesel production, including the various variables of transesterification process and a comparison of WCO biodiesel and petroleum diesel

Sustainability study of the processing of kitchen waste as a potential source of biofuel: biodiesel production from waste cooking oil (WCO)

One of the most concerned components in world’s food system challenges is food waste, and it is partic- ularly a critical issue in developed countries. Waste cooking oil (WCO) is one of the liquid food wastes that are recyclable. A proper recycling practice of WCO helps to reduce the adverse impact on environ- ment and it can be reused by converting it into industrial products such as biodiesel and soap. With the rising in cost of crude oil in the global market and depletion of conventional fuel, the world also is in need of alternative fuel to fulfil the global rising of energy demands. This paper studies on the potential of WCO as a source of biofuel by converting it to biodiesel by transesterification process. The acid value of the WCO is determined using standard titration method, in which, if the percentage of FFA is more than 2%, in which the WCO needs to undergo pre-treatment process. Sodium hydroxide is used as a catalyst and methanol as the reacting alcohol in transesterification. The characteristics of the biodiesel produced were tested and compared with the standard specification of the biodiesel; ASTM D6751 and EN 14214. From the experiment conducted, more than 90% of biodiesel yield can be obtained from the waste cook- ing oil. The properties of biodiesel that undergoes more washing process, such as acid value, density, kinematic viscosity, and cloud and pour points have values typically close to the ASTM D6751 and EN 14214 biodiesel standards, which can be seen in Sample 1. Producing biodiesel from WCO is one of the alternatives of disposing these waste products as it gives beneficial impacts to the environment. Since WCO is biodegradable, economical, environmental friendly and always available, the economic fea- sibility of biodiesel production from waste cooking oil is viable

Microencapsulation of Xanthone extracted from Garcinia Mangostana pericarp using freeze drying / Ummi Kalthum Ibrahim... [et al.]

Garcinia mangostana fruit is one of the most popular fruit and known as a tropical fruit that has high nutrition value and widely cultivated in the tropical rainforest of some Southeast Asian nations. The main objectives of this research were to identify the composition of extracted xanthones and to determine the antioxidant activity, total phenolic content, moisture content and antimicrobial activity of encapsulated Garcinia mangostana pericarp. Encapsulation process was done by using freeze drying technique. Antioxidant activity, total phenolic content, moisture content and antimicrobial activity of encapsulated xanthones analysis were conducted. The amount of xanthones was detected at range of 515 to 4000 cm⁻ 1 through Fourier transforms infrared spectroscopy (FTIR). The highest value of radical scavenging activity for non-encapsulated xanthones was 82.69% whereas 88.01% for encapsulated xanthones. The total phenolic content (TPC) was found 5.240 mg GAE/g and 6.359 mg GAE/g for non-encapsulated and encapsulated samples, respectively. In conclusion, encapsulated xanthones from Garcinia mangostana pericarp has high antioxidant activity and antibacterial properties which has potential to the manufacturing functional food, cosmeceutical and pharmaceutical industries

The effect of pH on color behavior of Brassica oleracea anthocyanin

Anthocyanins, as natural colorants are widely used in the food industry as an alternative to synthetic colorants due to their health benefits, beautiful color and safe to be consumed. Despite of the current challenge to maintain their color properties, the instability of the color can be utilized as an indicator in the food packaging industries. One of the factors which affect the color of the anthocyanins is the level of pH. In the food industry the anthocyanins color can easily change due to the various pH condition of the food product. Increasing the pH and temperature, during processing and storage would increase the degradation rates of anthocyanins. This study focuses on the anthocyanin color behavior at various pH in the liquid and solid phase. Samples of anthocyanin in aqueous solutions were studied at various pH levels between 1.0 to 14.0 at a period of 10 days. Colors were expressed by the CIELAB coordinates, color tone, color intensity and color lightness. Powdered anthocyanin exhibits more stable compared to juice anthocyanin at most pH values, showing no changes in color intensity and color tone and little changes in color lightness. The variation in the results suggested that further developments of anthocyanin as a potential pH color indicator in food packaging system are required