In vitro production of spotted sorubim (Pseudoplatystoma corruscans) fish silage supplemented with different levels of hydrolyzed corn starch or sugar cane molasses using five different species of lactic acid bacteria

Abstract

Fish processing generates a substantial amount of waste, leading to environmental concerns and economic losses. This study focuses on the valorization of co-products (mechanically separated meat (MSM) and protein concentrate (PC)) from spotted sorubim (Pseudoplatystoma corruscans) processing to produce biological silage. Substrates were supplemented with hydrolyzed corn starch (HCS) or sugarcane molasses (SCM) and inoculated with Pediococcus acidilactici, Oneococcus oeni, Lactobacillus sakei, Weissela viridensis or Lactobacillus acidophilus NRRL B-23431. Fermentations were conducted at 30°C for 4 days. Microbial counts (lactic acid bacteria, mesophilic bacteria, yeasts and molds), and proximate composition of the silages were analyzed. P. acidilactici exhibited robust growth in treatments containing 20 % and 10 % SCM across both MSM- and PC-based media, suggesting that HCS was not an effective growth inducer. On the other hand, L. sakei exhibited limited growth in all substrates. Moisture contents ranged from 78.50 % to 86.70 % and protein content from 26 % to 68 %. Lipid decreased during fermentation. The rapid metabolic activity at short fermentation times was very important to add value to these products, making the silages suitable for animal feed.