Effects of gamma irradiation on the composition and in vitro digestibility of crop by-products

Abstract Over the past decades, the agro-industrial by-products (AIBP) has received considerable attention. With this motivation, the aim of this study was to investigate the effect of AIBP as a source of non-fiber carbohydrates on biogas production kinetic, methane emission and fermentation characteristics. Experimental treatments were (1) Sugar beet pulp (SBP) (control), (2) Apple pomace (AP), (3) Orange pulp (OP, (4) 33% AP + 66% OP, (5) 50% AP + 50% OP and (6) 66% AP + 33%OP. For this work, we analyzed the data collected from the kinetics of digestion through biogas production, ex-vivo methane emission, in-vitro digestibility of dry matter and fermentation parameters. Field emission scanning electron microscope was used to show the nano structural differences of the AIBPs. Our results demonstrated the significant differences of the crude protein among the treatments (P < 0.05). Biogas production and methane emission were significantly higher in SBP and OP treatments (P < 0.05). The most eminent and the lowest amounts of acetate were observed for AP and OP (61.84 mmol/L, 58.15 mmol/L), respectively. More broken edges were obvious in OP images. particle size was rather smaller in SBP. Images of AP showed a sleek surface which may act as a shield preventing more digestion. Overall, beside reducing environmental contamination by AIBP, our results showed a positive effect of AIBPs on degradation and biogas kinetics, methane emission and in vitro fermentation parameters describing that they can be used as a good source of non-fiber energy sources.

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Valorization of Aquaculture By-Products of Salmonids to Produce Enzymatic Hydrolysates: Process Optimization, Chemical Characterization and Evaluation of Bioactives

Marine Drugs ◽

10.3390/md17120676 ◽

2019 ◽

Vol 17 (12) ◽

pp. 676 ◽

Cited By ~ 6

Author(s):

José Antonio Vázquez ◽

Carmen G. Sotelo ◽

Noelia Sanz ◽

Ricardo I. Pérez-Martín ◽

Isabel Rodríguez-Amado ◽

...

Keyword(s):

Rainbow Trout ◽

Protein Quality ◽

Chemical Characterization ◽

Enzyme Concentration ◽

In Vitro Digestibility ◽

High Concentration ◽

Small Peptides ◽

Molecular Weights ◽

By Products

In the present manuscript, various by-products (heads, trimmings, and frames) generated from salmonids (rainbow trout and salmon) processing were evaluated as substrates for the production of fish protein hydrolysates (FPHs), potentially adequate as protein ingredients of aquaculture feeds. Initially, enzymatic conditions of hydrolysis were optimized using second order rotatable designs and multivariable statistical analysis. The optimal conditions for the Alcalase hydrolysis of heads were 0.1% (v/w) of enzyme concentration, pH 8.27, 56.2°C, ratio (Solid:Liquid = 1:1), 3 h of hydrolysis, and agitation of 200 rpm for rainbow trout and 0.2% (v/w) of enzyme, pH 8.98, 64.2 °C, 200 rpm, 3 h of hydrolysis, and S:L = 1:1 for salmon. These conditions obtained at 100 mL-reactor scale were then validated at 5L-reactor scale. The hydrolytic capacity of Alcalase and the protein quality of FPHs were excellent in terms of digestion of wastes (Vdig > 84%), high degrees of hydrolysis (Hm > 30%), high concentration of soluble protein (Prs > 48 g/L), good balance of amino acids, and almost full in vitro digestibility (Dig > 93%). Fish oils were recovered from wastes jointly with FPHs and bioactive properties of hydrolysates (antioxidant and antihypertensive) were also determined. The salmon FPHs from trimmings + frames (TF) showed the higher protein content in comparison to the rest of FPHs from salmonids. Average molecular weights of salmonid-FPHs ranged from 1.4 to 2.0 kDa and the peptide sizes distribution indicated that hydrolysates of rainbow trout heads and salmon TF led to the highest percentages of small peptides (0–500 Da).

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Nutritional Value of Extruded Dog Food with Mechanically Separated Chicken Meat or Meat By-products.

10.20944/preprints201901.0189.v1 ◽

2019 ◽

Author(s):

Giorgia Meineri ◽

Pier Giorgio Peiretti ◽

Sonia Tassone ◽

Alessia Candellone ◽

Erica Longato ◽

...

Keyword(s):

Fatty Acid ◽

Chicken Meat ◽

In Vitro Digestibility ◽

Pet Food ◽

Dog Food ◽

Food Digestibility ◽

Valid Instrument ◽

By Products

The objectives of this study were: (a) to evaluate the effect of inclusion of mechanically separated chicken meat (MSCM) in dry dog food on fatty acid profile, in vivo and in vitro digestibility, and palatability as compared with dry dog food containing meat by-products (MBP); (b) to determine, whether or not, the inclusion of the one or the other ingredient changes the microbiology and the storage quality of the two food products; (c) to propose a new system (DaisyII Incubator) to measure the in vitro digestibility of the two products. Their similar chemical composition notwithstanding, the MSCM product had lower palatability but better nutritional quality (with higher polyunsaturated fatty acid [PUFA] content and lower saturated fatty acid [SFA] content) than the MBP product. Microbiological risk assessment showed no microbiological hazards for either product. After 6 months storage, polyamine values were found to be higher in the MSCM than in the MBP. Finally, the DaisyII Incubator proved a valid instrument for the study of in vitro digestibility also for dogs; since it provided data simply, quickly with less variability and cost than obtained with in vivo trials, it could represent the future for pet food digestibility studies. Our results indicate that inclusion of MSCM or MBP as the main protein ingredient in extruded pet food may be used advantageously in product formulations.

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