Effects of temperature, heating time and particle size on values of rumen undegradable protein of roasted soybean

Abstract

Roasted soybeans are commonly used in diets for dairy cows, but the processing conditions of roasted soybean and their effects on rumen undegradable protein (RUP) have not been fully understood. In this study, the effect of the processing of roasted soybean on RUP was examined through a factorial arrangement of treatments. The effects of roasting temperature (115 ºC, 130 ºC and 145 ºC), time of roasting (5, 10 and 15 min) and particle size of soybean (whole, coarse and fine) on the protein fractions of roasted soybean were analysed with the Cornell Net Carbohydrate and Protein System (CNCPS) and protein dispersibility index (PDI) methods. The whole, coarsely ground and finely ground soybean had mean particle sizes of 5.30 mm, 1.15 mm and 1.05 mm. The proportion of soluble protein was reduced with increasing temperature and time of roasting. The true protein with intermediate rates of degradation decreased with escalating temperatures, but increased when the time was raised and the particle size reduced. Also, the true protein level with slow rates of degradation was raised with increasing temperature and heating time, but reduced when decreasing the particle size. The undegradable true protein level, on the other hand, was increased by decreasing the particle size. The results of CNCPS and PDI revealed that the recommended method would be to use soybeans with a particle size of 1.15 mm, and to roast them at 115 ºC for 10 minutes. Furthermore, the results showed that different methods of processing used in soybean roasting could strongly affect RUP content.

Seeds of n-GM Soybean Varieties Cultivated in Poland and Their Processing Products as High-Protein Feeds in Cattle Nutrition

“…The limitation of the product's share in the composition of feed ration results from the high fat content and possible fragmentation of seeds. The results presented by Rafiee-Yarandi et al [63] showed that roasting at 115 • C for 10 min of full-fat soybeans crushed to a particle size of 1.15 mm preferably stabilizes the ratio of non-degradable protein content in the rumen to digestible protein in the small intestine, ensuring optimal protein nutritional values of such processed full-fat soybeans in cattle feeding. According to Tice [64], roasting of raw soybean seeds resulted in an increase of unsaturated fatty acids content in milk fat; additionally, the content of polyunsaturated fatty acids in milk increased compared to milk from cows fed with raw soybeans.…”

Effects of Clostridium autoethanogenum protein inclusion levels and processing parameters on the physical properties of low-starch extruded floating feed

“…The starch content of the feeds was measured et al (2013). The protein dispersibility index (PDI) was measured using the method described by Rafiee-Yarandi et al (2016). The foaming properties of protein materials were determined following the method of Lee et al (2006) but with some modifications.…”

Degradability of Rumen-Protected Soybean Meal with Different Temperatures and Heating Times in Bali Cattle

“…The reaction that occurs between the two groups will form a cross-link. The cross-links formed will cause a decrease in digestibility due to inhibition of enzyme penetration into the protein substrate or due to the closure of protein sites that can be attacked by enzymes (Palupi et al, 2007), thus decreasing protein solubility and increasing the rumen bypass protein (Reddy et al, 1993;Dhiman et al, 1997;Rafiee-Yarandi et al, 2016).…”