Pengaruh Fermentasi Fungi, Bakteri Asam Laktat dan Khamir terhadap Kualitas Nutrisi Tepung Sorgum

Abstract

Recently, food security problem in Indonesia is mainly due to the consumption dependence on rice and wheat, while the utilization of local sources of carbohydrates such as tubers and cereals are still limited. Sorghum is one of local cereal that potential to be developed as source of carbohydrates and protein. However, a problem encountered on utilising sorghum as food is the low protein digestibility. The objective of this study was to investigate the effects of fermentation of Rhizopus oligosporus, Lactobacillus plantarum, and Saccharomyces cerevisiae on nutritional quality and digestibility of sorghum flour. The procedure in this research were pre-treatment of sorghum grains, preparations of inoculum, solid state fermentation, liquid state fermentation, mixture solid-liquid fermentation of sorghum grains, flouring (draining and mashing), microbial (total plate count) and chemical analysis (proximate analysis, amino acid analysis, and protein digestibilty). Sorghum flour was made with 4 variations of treatments that was performed in triplo, i.e: control (without fermentation), liquid fermentation (with Lactobacillus plantarum and Saccharomyces cerevisiae), solid fermentation (with Rhizopus oligosporus), solid and liquid fermentation (with addition of Rhizopus oligosporus,Lactobacillus plantarum and Saccharomyces cerevisiae). The result showed that the number of microbes in fermented sorghum flour was still within the safety limits in accordance to SNI. The fermentation process did not significantly influence the levels of protein, carbohydrate, and fat of sorghum flour. During the fermentation of sorghum, the levels of the amino acids cysteine and lysine increased while several other amino acids decreased. Fermentation increased significantly the digestibility of sorghum protein up to 3,5-5 fold than control without fermentation.

ABSTRAK

Masalah ketahanan pangan di Indonesia saat ini diantaranya adalah pola konsumsi masyarakat sangat tergantung pada beras, terigu, dan belum luasnya pemanfaatan sumber karbohidrat lokal seperti umbi-umbian dan serealia. Sorgum adalah salah satu serealia lokal yang berpotensi dikembangkan menjadi sumber karbohidrat dan protein. Namun, salah satu kendala yang dihadapi dalam pemanfaatan sorgum sebagai bahan pangan adalah rendahnya daya cerna protein sorgum. Penelitian ini bertujuan menganalisis pengaruh fermentasi Rhizopus oligosporus, Lactobacillus plantarum, dan Saccharomyces cerevisiae terhadap kualitas nutrisi dan daya cerna protein tepung sorgum. Tahapan penelitian yang dilakukan yaitu pra-perlakuan biji sorgum, penyiapan inokulum, fermentasi padat, fermentasi cair, fermentasi campuran padat dan cair terhadap biji sorgum, penepungan (pengeringan dan penggilingan), analisis mikrobiologi (total koloni mikroba) dan analisis kimia (kadar proksimat, asam amino, dan daya cerna protein). Pembuatan tepung sorgum dilakukan dengan empat perlakuan secara triplo yaitu kontrol (tanpa fermentasi), fermentasi cair (dengan Lactobacillus plantarum dan Saccharomyces cerevisiae), fermentasi padat (dengan Rhizopus oligosporus), dan fermentasi campuran padat dan cair (dengan Rhizopus oligosporus, Lactobacillus plantarum dan Saccharomyces cerevisiae). Hasil penelitian menunjukkan bahwa jumlah mikrobia pada tepung sorgum fermentasi masih dalam batas aman sesuai dengan SNI. Proses fermentasi tidak berpengaruh signifikan terhadap kadar protein, karbohidrat, dan lemak pada tepung sorgum. Selama fermentasi sorgum, kadar asam amino sistein dan lisin mengalami peningkatan sedangkan beberapa asam amino lainnya menurun. Proses fermentasi berpengaruh signifikan dalam meningkatkan daya cerna protein sorgum sebesar 3,5-5 kali lipat dibandingkan dengan kontrol tanpa fermentasi.