餐厨垃圾源黑水虻的营养组成及虫沙的化学成分分析

Analysis of nutritive composition of black soldier fly larvae derived from food waste and chemical components of sandworm

为了探究餐厨垃圾源黑水虻的营养组成及虫沙的化学成分,试验选取14日龄的餐厨垃圾源黑水虻幼虫鲜样烘干后制备的虫粉(研磨粉碎、压榨脱脂后研磨粉碎),进行虫粉安全性(重金属含量和细菌总数)分析,测定脱脂处理前后黑水虻营养成分(粗蛋白、粗灰分和粗脂肪)、脂肪酸及氨基酸含量,以及黑水虻虫沙中重金属(汞、砷、镉、铅、铬)含量、虫沙的化学成分(有机质、水分、总养分、有机碳和盐)含量及pH值。结果表明:餐厨垃圾源黑水虻重金属含量及细菌总数符合《饲料卫生标准》(GB 13078—2017)要求。未脱脂黑水虻粗蛋白、粗灰分和粗脂肪含量分别为42.05%、6.36%和30.34%,脱脂黑水虻分别为54.40%、8.66%和11.15%,脱脂黑水虻的粗蛋白含量高于豆粕(P<0.05)和鱼粉(P>0.05)。与豆粕和鱼粉比较,未脱脂黑水虻幼虫虫粉中含有较高水平的饱和脂肪酸(59.218%),脂肪酸主要由月桂酸、油酸、棕榈酸、亚油酸组成,与豆粕、鱼粉脂肪酸组成差异较大。黑水虻幼虫虫粉总氨基酸含量为38.25%,主要由谷氨酸、天冬氨酸、组氨酸、亮氨酸组成,必需氨基酸/非必需氨基酸为1.0,脱脂处理后总氨基酸含量为50.04%,且脱脂处理并未改变黑水虻氨基酸组成及比例,其氨基酸组成与豆粕、鱼粉相近。餐厨垃圾源黑水虻虫沙呈弱碱性,有机质含量为84.87%,水分含量为26.09%,总养分含量为6.54%,未检出砷、汞、镉且铅、铬含量较低,均符合《有机肥料》(NY 525—2012)的要求,但含盐量高。说明餐厨垃圾源黑水虻是一种高脂肪、高蛋白饲料,脱脂处理后,有潜力作为蛋白质饲料原料替代豆粕、鱼粉;同时餐厨垃圾源黑水虻虫沙可作为有机肥施用,但必需进行脱盐处理。

To investigate the nutritive composition and chemical composition of black soldier fly larvae derived from food waste and sandworm, insect meal(crush by grinding, crush by grinding after press and degreasing) prepared by fresh larvae from 14-day-old food waste source black soldier fly was collected for safety analysis(heavy metal content and total bacteria counts). The nutrient compositions(crude protein, crude ash and crude fat) and the contents of fatty acids and amino acids in black soldier fly larvae were determined before and after degreasing process. In addition, the contents of heavy metals(Hg, As, Cd, Pb, and Cr) and the chemical analysis(organic matter, moisture, total nutrient, organic carbon, and salt) and pH value of sandworm were examined. The results showed that the heavy metal content and total bacteria counts of black soldier fly larvae derived from food waste met the requirements of feed hygienic standard(GB 13078—2017). The contents of crude protein, crude ash and crude fat of undegreased black soldier fly larvae were 42.05%, 6.36% and 30.34%, respectively, while the contents of crude protein, crude ash and crude fat of degreased black soldier fly larvae were 54.40%, 8.66% and 11.15%, respectively. The protein content of degreased black soldier fly larvae was higher than that of soybean meal(P<0.05) and fish meal(P>0.05). Compared with soybean meal and fish meal, a higher level of saturated fatty acids(59.218%) was observed in the undegreased black soldier fly larvael. From the perspective of single fatty acid composition, it is mainly composed of lauric acid, oleic acid, palmitic acid, and linoleic acid, which is quite different from that of soybean meal and fish meal. The content of total amino acid in black soldier fly larvae was 38.25%, which was mainly glutamic acid, asparaginic acid, histidine and leucine, and the ratio of essential amino acid to non-essential amino acid was 1.0. The content of amino acid was 50.04% after degreasing treatment, and the degreasing treatment did not affect the composition and proportion of amino acid in black soldier fly larvae. The composition of amino acid in degreased black soldier fly larvae was equivalent to soybean meal and fish meal. No arsenic, mercury and cadmium were detected, and there were a low level of lead and chromium in the sandworm excreted from the black soldier fly larvae derived from food waste. The sandworm was weakly alkaline, the contents of its organic matter, moisture and total nutrient were 84.87%, 26.09%, 6.54%, respectively, which met the standards of organic fertilizer(NY 525—2012), but the salt content was high. The results demonstrated that the black soldier fly larvae derived from food waste was a high-fat and high-protein feedstuff, which could be used as protein feed material to replace the soybean meal and fish meal after degreatement. At the same time, it could be used as organic fertilizer, but it must be desalted.