Thermomechanical and enzyme-facilitated processing of soybean meal enhanced in vitro kinetics of protein digestion and protein and amino acid digestibility in weaned pigs

Abstract

Soybean meal (SBM) contains anti-nutritional factors (ANF) that may limit kinetics and total extent of protein digestion in pigs. This study evaluated effects of thermo-mechanical and enzyme-facilitated (TE) processing on in vitro kinetics of crude protein (CP) digestion and CP and amino acid (AA) digestibility in weaned pigs. Each batch of SBM (48% CP) was divided into 2 parts: non-processed SBM as control vs. thermo-mechanical and enzyme-facilitated processed soybean meal (TES) as experimental group. For digestion kinetics, samples (3 batches of non-processed SBM vs. TES) were incubated in triplicate sequentially with pepsin at pH 3.5 for 1.5 h (stomach phase), and subsequently with pancreatin and bile extract at pH 6.8 for 0, 0.5, 1, 2, 4, or 6 h (small intestine phase). Protein was classified into CPfast, CPslow, and CPresistant corresponding to CP digested within the first 0.5 h, from 0.5 to 4 h, and after 4 h plus undigested CP, respectively. Eight weaned barrows (Large White × Duroc, 9.43 ± 0.40 kg) were surgically fitted with a T-cannula at the terminal ileum. Pigs were randomly assigned to a Youden square with 3 diets over 4 periods. The 3 diets were an N-free diet and 2 diets using 40% SBM or TES as sole source of AA with Cr2O3 as an indigestible marker. Each period included sequentially a 5-d adaptation, 2-d collection of feces, and 2-d collection of ileal digesta. The TE processing reduced ANF content in TES by 91% for lectin, 22% for trypsin inhibitor activity, 75% for β-conglycinin, and 62% for glycinin compared to SBM. In vitro, TE processing increased (P < 0.05) digested CP by 5.6% and enhanced kinetics of CP digestion by tending to increase (P = 0.056) CPfast by 25% and reducing (P < 0.05) CPslow and CPresistant by 48 and 11%, respectively. In pigs, TE processing increased (P < 0.05) apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of CP in TES by 2.3 and 2.1%, respectively. The TE processing increased (P < 0.05) AID and SID of all AA up to 3.3%, except for AID of Pro and SID of Pro, Gly, and Cys. The TE processing did not change reactive Lys or Lys:CP but increased (P < 0.05) SID of Lys and reactive Lys by 3%. Combined, the greater in vitro digestion kinetics matched the greater in vivo AID and SID of CP in TES and lower ANF compared to SBM. Thus, TE processing created a protein source that is digested faster and to a greater extent than SBM, thereby lowering the chance of protein fermentation.

Impact of cooking on the protein quality of Russet potatoes

“…These authors also demonstrated that the differences in IVPD values were consistent with differences observed for standardized ileal digestible coefficients for crude protein, being 88.4% and 90.3% (p < .001) for the conventional and advanced processed soybean meal, as measured in an in vivo pig study (Nu et al, 2020). In the current study, the IV-SGPD% values for all the cooked potato samples were significantly different from the raw control (Table 3), with all methods being higher than the control.…”

“…The use of the IV-SGDPD% method represents a step up in complexity in that, while still being a static method, it employs a two-stage digestion protocol (gastric and intestinal), with the addition of α-amylase. Nu et al (2020) used a similar method to compare the in vitro protein digestibility of conventional and thermomechanical and enzymefacilitated processed soybean meal for pigs and determined that the advanced processing methods used for soybean preparation yielded a product with higher IVPD (74.6% vs. 81.1% at 6 h total digestion).…”

Feeding coproducts to pigs to reduce feed cost and reach sustainable food production

“…In addition, fractionation processes can generate novel high-protein DDGS fractions ( Cristobal et al, 2020 ) with enriched P content. Likewise, enzyme and extrusion technologies have generated highly digestible soy protein concentrates as novel feed ingredients for nursery pigs ( Ton Nu et al, 2020 ) to further expand the array of soy protein feedstuffs ( Yáñez et al, 2019 ). Finally, recycled coproducts (food waste) from the food industry might become important for the feeding of pigs ( Woyengo et al, 2015 ; Fondevila et al, 2021 ).…”

Effect of Fiber Fermentation and Protein Digestion Kinetics on Mineral Digestion in Pigs

“…As illustrated in Table 5 , studies have examined digestion kinetics of starch and protein, and fiber fermentation. Furthermore, quantitative information on differences in nutrient digestion or fermentation kinetics among different feedstuffs or purified sources were classified based on fast, slow, and resistant digestible nutrients [ 38 , 39 , 41 , 61 , 67 , 68 ]. Nevertheless, further research into the role of the synergistic effects of nutrient digestion is required because undigested nutrients may affect the digestion of other nutrients [ 18 ].…”

“…The ANF may modulate the digestion and utilization of dietary protein and AA. Effects of thermomechanical and enzyme-facilitated processed SBM compared with non-processed SBM on in vitro kinetics of protein digestion and protein and AA digestibility in weaned pigs have previously been studied [ 39 ]. Processing reduced the ANF content (lectin, trypsin inhibitor activity, β-conglycinin, and glycinin) compared with non-processed SBM, and increased digested CP, tended to increase fast-digestible CP, and reduced slow and resistant CP compared with non-processed SBM.…”