Producing more food for a growing population in the coming decades, while at the same time combating environmental issues, is a huge challenge faced by the worldwide population. The risks that come with climate change make the mission more daunting. Billion tons of agriculture by-products are produced each year along the agricultural and food processing processes. There is a need to take further actions on exploring the inner potential of agrowaste to stand out as food ingredient to partially or fully substitute the foods in orthodox list. Some of the agro-waste contains the most valuable nutrients in the plant and it is truly a "waste" to dispose any of them. Furthermore, the paper aims at discussing the possible methods of modification to improve the safety and feasibility of the agro-waste either through physical, chemical or microbiological ways. The safety issues and bioactivity contains in the agro-waste also been discussed to present the better overall ideas about the employing of agro-waste in food applications.

This paper examines the interactions of degumming and bleaching processes as well as their influences on the formation of 3-monochloropropane-1,2-diol esters (3-MCPDE) and glycidyl esters in refined, bleached and deodorized palm oil by using D-optimal design. Water degumming effectively reduced the 3-MCPDE content up to 50%. Acid activated bleaching earth had a greater effect on 3-MCPDE reduction compared to natural bleaching earth and acid activated bleaching earth with neutral pH, indicating that performance and adsorption capacities of bleaching earth are the predominant factors in the removal of esters, rather than its acidity profile. The combination of high dosage phosphoric acid during degumming with the use of acid activated bleaching earth eliminated almost all glycidyl esters during refining. Besides, the effects of crude palm oil quality was assessed and it was found that the quality of crude palm oil determines the level of formation of 3-MCPDE and glycidyl esters in palm oil during the high temperature deodorization step of physical refining process. Poor quality crude palm oil has strong impact towards 3-MCPDE and glycidyl esters formation due to the intrinsic components present within. The findings are useful to palm oil refining industry in choosing raw materials as an input during the refining process.

The extents of the oxidation and polymerization processes were examined in refined, bleached, and deodorized palm olein (RBDPO) to determine the impact of frying different foods on frying oil stability, particularly the formation of polar lipid fraction and short chain fatty acid upon frying, and at the same time to evaluate its discarding point. Sliced potatoes (SP) and chicken breast meat (CBM) were fried for 200 min/day for seven consecutive days using RBDPO at 180 °C without any oil replenishment. The amounts of total polar compound (TPC), polymerized triacylglycerols (PTG), and short-chain fatty acid (caprylic acid) that formed were significantly (p < 0.05) higher in the RBDPO used to fry SP compared to CBM. The TPC in the RBDPO used to fry SP exceeded the limit of rejection for human consumption (>25% polar compounds) on the seventh day of frying. In addition, the amounts of epoxy, keto, and hydroxy acids that formed were significantly (p < 0.05) higher in the RBDPO used to fry CBM compared to SP. RBDPO also exceeded the safety limit when the concentration of epoxy acids respectively reached 7.4 g/kg and 8.8 g/kg after frying SP and CBM for seven days.

No abstract

In this study, the safety and quality of commercial cooking oils were evaluated. The emphasis of this evaluation was on the presence of oxidation and polymerization products in fresh oils, although the analyses were often conducted on used frying fats and oils. This was because polymerized triacylglycerols (PTGs) and monomeric oxidized triacylglycerols (oxTAGs) have been proposed as potential indicators of the adulteration of palm olein. The oil quality was evaluated based on PTG content, the presence of epoxy, keto, and hydroxy acids, fatty acid composition, and smoke point. Principal component analysis (PCA) was conducted to identify the relationships among the analytical parameters. The total polar compound content of all fresh oil samples was within the safety limit for human consumption (< 25% polar compounds). TAG oligomers or epoxy, keto, or hydroxy acids were not detected in any of the fresh oil samples. Most of the packet oils had lower smoke point (< 200°C) and linoleic acid content than the bottled oils. The pure palm olein samples were found to be better in terms of overall oil quality, as indicated by the PCA biplots of all analytical parameters.