Fermentation using Rhizopus oligosporus to improve the nutritional values of kangkong seed as livestock feed ingredients

Kangkong (Ipomoea reptans Poir.) is a kind of vegetable plant consumed widely in Asia, while in other countries it is considered a weed. Kangkong is popular to be cultivated especially in Southeast Asia and its seeds are produced continuously. Kangkong seeds will be selected by the seed company and will be discarded if it is of low quality. These discarded seeds are considered a byproduct. Kangkong seeds contain 13.46% protein and 15.87% crude fiber. The high crude fiber and low protein content of kangkong seed are the limitations to utilizing it as a feed ingredient. Then solid-state fermentation by using fungi is used to improve its nutrients. Rhizopus oligosporus is a fungus that is commonly used to increase the nutritional value of a food ingredient. This study aims to evaluate the effect of fermentation using Rhizopus oligosporus on crude protein, crude fiber, crude fat, and amino acid content of kangkong seed. This study used a 3 x 3 factorial design. The first factor was the dosage of inoculum which consisted of three levels, namely 0.1, 0.2, and 0.3g /100g of kangkong seeds. The second factor was the fermentation time, namely 24, 48, and 72 hours. The research was conducted using a Completely Randomized Design (CRD). The results showed that the fermentation of Kangkong seed by using Rhizopus oligosporus improved crude protein by 61.70% and reduce crude fiber by 66.03% at an inoculum dose of 0.3g fermented for 72 hours. Kangkong seeds contain 8 of 10 types of essential amino acids with the highest proportions are leucine, arginine, and phenylalanine, respectively.