Effect of Different Extrusion Processing Parameters on Physical Properties of Soy White Flakes and High Protein Distillers Dried Grains-Based Extruded Aquafeeds

Abstract

Nutritionally balanced ingredient blends for catla (Catla catla), belonging to the family Cyprinidae, were extruded using single screw extruder. The extrusion was carried out at five levels of soy white flakes content (21%, 29%, 40%, 52%, and 59% db), five levels of moisture content (15, 19, 25, 31, and 35% db) and five levels of barrel temperature (100, 110, 125, 140, and 150 ºC) using three different die nozzles (having L/D ratios 3.33, 5.83, and 7.25). Blends with net protein content of 32.5% contains soy white flakes, along with high protein distillers dried grains (HP-DDG), corn flour, corn gluten meal, fish meal, vitamin, and mineral mix. A central composite rotatable design (CCRD) and response surface methodology (RSM) was used to investigate the significance of independent and interaction effects of the extrusion process variables on the extrudates physical properties namely pellet durability index, bulk density, water absorption and solubility indices and expansion ratio. Quadratic polynomial regression equations were developed to correlate the product responses and process variables as well as to obtain the response surfaces plots. The independent variables had significant (P < 0.05) effects on physical properties of extrudates: (i) higher soy white flakes content increased the pellet durability index and water absorption index, but decreased the water solubility index, (ii) higher temperature decreased pellet durability index, bulk density and water solubility index, (iii) increased L/D ratio from 3.33 to 7.25 increased the pellet durability index, expansion ratio but decreased the bulk density of the extrudates.

Effect of feed moisture, extrusion temperature and screw speed on properties of soy white flakes based aquafeed: a response surface analysis

“…shows that at low temperature, with increase in soy white flakes content, pellet durability index initially decreased and after reaching a minimum it increased further. Similar findings were observed in our previous study . ANOVA showed that moisture content had no significant effect on pellet durability index and hence response surface plots of interaction effect involving moisture content are not shown.…”

“…The effect of soy white flakes content and different die nozzles at constant speed (150 rpm) were evaluated. A positive effect on the durability and expansion ratio of aquafeed with increase in die aspect ratio of nozzle was observed . However, the effect of various levels of screw speed on the properties of aquafeed was not studied.…”

“…Indubitably, with the increasing rate of farmed fish production and consequently the rising prices of fishmeal, the continued use of fishmeal as the main protein source of the feed will no longer be ecologically and economically sustainable in the long run. Soy white flakes and high protein–distiller dried grains (HP‐DDG) contains a high amount of protein and are thus a possible alternative source of protein for aquaculture feeds . Use of soy products like full fatted soybean meal, defatted toasted soybean meal (SBM) and defatted untoasted soybean meal or white flakes (WF) is becoming common .…”

“…Soy white flakes and high protein–distiller dried grains (HP‐DDG) contains a high amount of protein and are thus a possible alternative source of protein for aquaculture feeds . Use of soy products like full fatted soybean meal, defatted toasted soybean meal (SBM) and defatted untoasted soybean meal or white flakes (WF) is becoming common . Romarheim et al found that extrusion of WF diet increased the digestibility of protein and all amino acids whereas extrusion of fishmeal and SBM had no significant effect on amino acid digestibility.…”

Effects of processing conditions on the system parameters during single screw extrusion of blend containing apple pomace

“…Legumes such as soybean are rich source of protein. Soybean in different forms (Bookwalter, Mustakas, Kwolek, Mcghee, & Albrecht, ; Chiang, ; Iwe et al, ; Lobato, Anibal, Lazaretti, & Grossmann, ; Singh & Muthukumarappan, ; Yu, Meng, Ramaswamy, & Boye, ) have been extensively used as a major ingredient during extrusion.…”