Bioconversion of Onion Waste to Valuable Biosugar as an Alternative Feed Source for Honey Bee

Abstract

White sugar is the main commodity used to feed honey bees during the off-season as a nectar substitute. However, the price of sugar is increasing every year, thereby making bee keeping an expensive enterprise. Hence, it is necessary to find an alternative bee feed that is cheaper than sugar. The study aims to determine the potential of an alternative bee feed from renewable resources using onion waste (OW), which has a similar sugar composition to that of honey. The OW produces biosugar from in-house produced enzymes at a 90% conversion rate. The efficiency of enzymatic hydrolysis increases by more than 2 times after popping pretreatment. Furthermore, a removal rate of 98.5% for sulfur compounds, which caused the distinctive smell of onion, is obtained using a continuous column process with an activated carbon-containing alginate bead (AC-AB) adsorbent. In addition, after popping pretreatment and continuous AC-AB adsorbent column treatment, the feed intake is increased and the mortality is decreased by 3.2 times compared to that of none-popping and desulfurization treatment. Moreover, the combination of alternative feed with pollen decreases the mortality rate to almost 5.4 times. The results clearly demonstrates that OW can be a possible alternative feed source for honey bees.