Protein utilisation, lysine bioavailability and nutrient digestibility of shrimp meal in growing pigs

Characterisation of Tenebrio molitor Reared on Substrates Supplemented with Chestnut Shell

Tenebrio molitor larvae represent a sustainable protein source for food and feed. The aim of this study was to evaluate the supplementation of chestnut shell, a by-product of the agro-industrial chain, in growth substrates for T. molitor larvae rearing. Seven-week-old larvae were reared on three different growth substrates: the control group (CTRL) was fed wheat bran, treatment group one was fed wheat bran supplemented with 12.5% w/w chestnut shell (TRT1), and treatment group two was fed wheat bran supplemented with 25% w/w chestnut shell (TRT2). Larval weight, substrate consumption, and mortality were recorded weekly. After 14 days, insect meals were produced for bromatological and colorimetric analysis, and bacterial inhibition activity assay using a microdilution method. The amino acid profile of insects was determined using quantitative nuclear magnetic resonance spectroscopy. Our results showed a lower feed conversion ratio and higher larval survival rate % in TRT2 compared to CTRL (p < 0.05). Proteins and lipids of TRT2 were higher than other groups (p < 0.05). Important differences were observed in the amino acid profile of TRT1 and TRT2 compared to CTRL (p < 0.05). TRT1 and TRT2 showed higher E. coli inhibitory activity than CTRL (p < 0.05). In conclusion, chestnut shell supplementation improved the survival and functional characteristics of larvae and likely impacted the insects' metabolism.

Improvement in Nutritional Quality of Shrimp Meal with Autoclave and Chemical Treatments: an in vitro Study

The present study was conducted to improve the nutritional quality of shrimp meal (SM) comprising of heads with hulls of black tiger shrimp (Penaeus monodon) waste by autoclaving and chemical treatments. The sun-dried SM was divided into 5 treatment groups, such as 1) control (untreated), 2) autoclaved (autoclaved at 121°C for 10 min), 3) NaOH (treated with 3% NaOH), 4) HCl (treated with 3% HCl) and 5) formic acid (treated with 3% formic acid) groups. After treatment, they were ground to pass through 1.0 mm mesh screen and then used for analyses of chemical composition and in vitro dry matter (DM) and CP digestibilities. Data were subjected to one-way ANOVA and differences among treatment means (P<0.05) were distinguished with Tukey's test. There were no significant difference in chemical composition and in vitro DM and CP digestibilities between control and autoclaved groups, except ether extract level (P<0.05), suggesting that autoclaving affected the nutritional quality of SM little. NaOH group exhibited significantly decreased CP level and in vitro DM digestibility, increased crude ash (CA) level and unchanged in vitro CP digestibility, comparing with control group. These results suggest that NaOH treatment affected the nutritional quality of SM adversely. HCl and formic acids groups showed significantly increased CP level and in vitro digestibilities of DM and CP, and decreased CA level, showing that acid treatment can improve nutritional quality of SM: formic acid treatment may be more effective because of the greater values in CP level and digestibilities and decreased crude fibre level which was not observed in HCl group (P<0.05). The results obtained here suggest acid, especially formic acid, treatment is promising to improve the nutritional quality of SM but autoclaving and NaOH treatments.

Protein-Rich By-Products: Production Statistics, Legislative Restrictions, and Management Options

Congruent to a rapidly growing population is the generation of horticultural and agricultural by-products and waste. The modern-day food cycle includes agricultural production, postharvest handling and storage, food processing and packaging, and distribution and retail, ending with consumption and waste disposal. Of these, agricultural production and postharvest handling and storage result in unintended losses and by-products whereas the other steps generally result in food waste. Approximately one-third of the worldwide food production is wasted each year. Although it is most desirable to prevent waste and by-product formation, followed by reuse or recycling, the formation of by-products and waste is inevitable, and management options must be innovative and also meet legislative requirements. However, management options are mostly a compromise between what is viewed acceptable based on legal requirements and local perceptions, and what is deemed technologically and financially feasible.