Impact of particle size, thermal processing, fat inclusion, and moisture addition on starch gelatinization of broiler feeds

Effect of Thermal Processing, Press Throughput and Roller-Die Gap on Physicochemical Properties of Broiler Feed Pellets

“…Similar results were observed in previous study done by Muramatsu et al [12], where pellets from conditioned feed at 82 °C for 15 s were compared to those manufactured from conditioned feed under the same parameter and sequentially submitted to expander at 110 °C for 5 s. These authors reported that the use of expander combined with conditioner reduced the amount of fines in pelleted feed up to 200 g/kg of feed, and PDI was enhanced from 69% to 87% when compared to single conditioning. Also a survey held in North American feed manufacturers indicated that diets processed on expander before pelleting when compared to single conditioning-pelleting improved pellet quality by 15%-25% [26].…”

“…As expected, protein solubility loss was evident in conditioning-expanding-pelleting treatment (70.0%), whereas in conditioning-pelleting treatment, the damages were the minimum (77.3%). Muramatsu et al [12] also described reductions in protein solubility when diets were submitted to thermal processing. These authors compared conditioning-expanding-pelleting, where feed was firstly conditioned at 82 °C for 15 s and then expanded at 110 °C for 5 s, with conditioning-pelleting process, and observed a greater loss in the expander than in single conditioning (64.5% versus 68.6% protein solubility in KOH).…”

“…For this reason, efficient pellet production is aimed and pellet press should deliver a high yield of dust free and resistant pellets to optimize the feed mill operations. Besides the types of ingredients, amount of added fat, feed particle size, die's compression rate, conditioning temperature and moisture or binders inclusion, of which effects have been extensively reported by many authors [1][2][3][4][5][6][7][8][9][10][11][12][13], other factors, such as expander heat treatment, roller to die distance and press throughput, also affect pellet physicochemical properties.…”

“…Muramatsu et al [12] observed that conditioning-expanding-pelleting process led to an additional 205 g of intact pellet/kg of feed, when compared to a conventional conditioning-pelleting process. In a similar way, Lundblad et al [17] compared pellet quality in feed conditioned at 82 °C for 20 s versus feed submitted to the same conditioning parameters but further expanded at 121 °C.…”

“…On the other hand, the aggressive heat treatment in expander induces greater denaturation of dietary proteins. Therefore, conditioned-expanded feed show reduced in vitro assessment of the feed protein solubility in KOH, when compared to conditioned feed [12]. Veloso et al [18] observed that after an expander treatment at 130-136 °C, soybean meal protein solubility in KOH decreased from 80.6% to 64.1%.…”