Effect of initial glucose concentration and inoculation level of lactic acid bacteria in shrimp waste ensilation

In this research, shrimp waste was fermented with 3 species of symbiotic lactic acid bacteria, namely Streptococcus thermophilus, Lactobacillus acidophilus and Lactobacillus bulgaricus. The ingredient changes occurring in the fermentation process were investigated. Results showed that the production of lactic acid in the fermentation process was remarkably improved, with the pH decreasing rapidly to 4.25 within 8 h, the lowest pH reaching 3.22, and the titratable acidity reaching 25.0 mmol/100ml. The improved acidic environment promoted the removal of calcium and protein, with 91.3% calcium, 97.7% protein and 32.3% carotenoid removed from shrimp waste after 168 h fermentation. The putrefaction was effectively prevented and the TVBN level was low throughout the whole process. Glucose was consumed rapidly in the earlier phase of the fermentation; about 69.4% glucose was consumed in the initial 24 h. The consumption of glucose was in well accordance with the growth of lactic acid bacteria, the removal of calcium and the increasing of titratable acidity. The amino nitrogen content kept increasing within 48 h, thereafter it came to decrease. 88.4% of peptides in the hydrolysate ranged between 1000 ~ 10000 Da, 10.2% smaller than 1000 Da, and 3.44% larger than 10000 Da.

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Aspen Plus Simulation Strategies Applied to the Study of Chitin Bioextraction from Shrimp Waste

Food Technology and Biotechnology ◽

10.17113/ftb.57.02.19.6003 ◽

2019 ◽

Vol 57 (2) ◽

pp. 238-248

Author(s):

David Gómez-Ríos ◽

Grace Navarro ◽

Paola Monsalve ◽

Rolando Barrera-Zapata ◽

Rigoberto Ríos-Estepa

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

Mixed Culture ◽

Aspen Plus ◽

Pacific White Shrimp ◽

Production Costs ◽

Raw Material ◽

Shrimp Waste ◽

Gross Margin ◽

The Impact

Chitin is an aminopolysaccharide of industrial interest commonly obtained from shrimp processing waste through chemical or biotechnological means. Current environmental concerns offer a stimulating perspective for chitin bioextraction with lactic acid bacteria since a considerable reduction in the use of corrosive and pollutant products is possible. Nevertheless, the efficiency of this bioprocess is still a matter of discussion. In this work, the experimental studies of chitin bioextraction from Pacific white shrimp (Litopenaeus vannamei) waste with a mixed culture of Lactobacillus plantarum, Lactobacillus bulgaricus and Streptococcus thermophilus are used in process simulation using Aspen Plus software for the analysis of the potential application of a bioprocess on plant scale. The experimental results of characterization in shake flasks and 1-litre bioreactor indicated that 50 h of fermentation with the mixed culture of lactic acid bacteria was enough to extract more than 90 % of minerals and proteins from the shrimp waste. The use of experimental parameters in the simulation allowed a reliable representation of the bioprocess yielding normalized root mean square values below 10 %. Simulation was used for the assessment of the impact of the raw material variability on the production costs and gross margin. In this regard, the gross margin of the operation ranged from 42 to 52 % depending on the raw material composition and product yield

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