Improving fiber utilization from rapeseed and sunflower seed meals to substitute soybean meal in pig and chicken diets: A review

Food-grade rapeseed cake particles: Production, physicochemical characteristics, and emulsifying properties

Rapeseed cake is rich in dietary fibers and proteins, but is predominantly used as fertilizer, with limited utilization in other applications. This study aimed to develop a food-grade holo-cellulose rapeseed cake fibrous particles stabilizer using hush pre-treatment (sequential alkali-acid, and heat), followed by ultrasonic cavitation (USC) or high-pressure microjet (HPM) processing. The pretreatment improved particle suspension stability (ζ-potential: -1.9 ± 1.5 mV to -42.5 ± 2.0 mV) and hydrophobicity (contact angle: 59.6 ± 1.9° to 81.3 ± 2.2°), endowing the particles with excellent emulsifying properties. Subsequent USC and HPM treatments decreased particle size and improved suspension stability further. The treated particles showed an octopus-like entangled enabling stable anchoring at the interface of oil and water. These particles formed a rigid network, contributing to the formation of robust emulsion gels. This study provides a feasible strategy for the advanced processing of rapeseed cake, expanding its potential applications in gel-based food industry and, promoting its high-value applications.

Fibre-rich ingredients differing in physicochemical properties modulate digesta transit and digestion kinetics in pigs

Physicochemical properties of fibres can affect digestive processes such as digesta transit, thereby affecting nutrient digestion kinetics. We evaluated the effects of (1) insoluble fibres differing in cell wall composition and physicochemical properties; wheat straw (WS), softwood flour (WF), and sunflower seed hulls (SF), and (2) addition of pectin to coarse insoluble fibres from straw (WSP), on the mean retention time (MRT) of digesta fractions and nutrient digestion throughout the gastrointestinal tract (GIT) of pigs. Twenty-four boars (49.1 ± 2.96 kg) were allocated to one of four diets, containing either 138 g/kg of WF, 144 g/kg of SF, or 150 g/kg of WS without or with the addition of 100 g/kg high-methylated pectin. The apparent total tract digestibility of nutrients was evaluated by quantitative faecal collection. After feeding diets supplemented with tracers, pigs were dissected following a frequent feeding procedure to approach steady-state passage of digesta, and assess MRT of liquids (Yb-EDTA), fine solids (TiO2), and insoluble fibrous particles (Chromium mordanted fibres) throughout the GIT. Unlike coarse WS, no differences in pH nor DM were observed between the proximal and distal stomach for WSP, and fine WF and SF (P > 0.05). Compared with WS, WF and SF reduced the MRT of fine solids (-01:51 to 01:03 h:min; P ≤ 0.05), and fibrous particles (-03:14 to 02:23 h:min; P ≤ 0.05) in the proximal and distal stomach, decreasing their separation, especially in the distal stomach (-01:30 to 01:20 h:min; P ≤ 0.05). Addition of pectin to WS reduced separation between fine solids and liquids in the distal stomach (-43 min; P ≤ 0.05), increased starch digestibility in the mid-small intestine (SI; +9%-units; P ≤ 0.05) but not at the end of the SI, and reduced total tract digestibility of nitrogen (-8%-units; P ≤ 0.05), reflecting a lower ileal digestibility (-8%-units). In the large intestine (LI), coarse WS reduced the MRT of digesta phases compared with fine WF and SF (-17:38 to 08:08 h:min). Regardless of origin, fermentation of insoluble fibres was poor (≤19%), while complete fermentation of pectin did not impact the fermentation of WS. In conclusion, fine WF and SF accelerated the emptying of solids and suppressed regional differences in pH in the stomach, and delayed digesta transit in the LI, compared with coarse straw. Pectin addition to coarse straw reduced gastric sieving between fine solids and liquids, and increased starch digestibility in the proximal SI.

Partial replacement of soybean meal with mixed plant proteins yields comparable growth and carcass quality in growing-finishing pigs

Objective

This study evaluated the impacts of partial replacement of soybean meal with different concentrations of mixed plant protein products (rapeseed meal (RSM) - palm kernel meal (PKM) -distillers dried grains with soluble (DDGS)) on growth performance and carcass quality of growing-finishing pigs.

Methods

A total of 180 crossbred [Yorkshire x Landrace] pigs with average initial weight of 29.72 + 1.65 Kg were randomly assigned to one of five dietary treatment groups on the basis of weight and sex, and the experimental duration was 105 days. The basal diet (C23ON) of growing and finishing pigs were partially replaced with increasing level of RSM-PKM-DDGS (1 to 5% for growing pigs, and 2 to 6% for finishers). Each treatment group had 9 replicate pens, each containing 2 barrows and 2 gilts. During the 15-week trial, body weight (BW), average daily gain (ADG), average daily feed intake (ADFI), and feed conversion ratio (FCR) were calculated for the periods of weeks 0-5, weeks 5-10, week 10-15, and for the entire experimental period.

Results

The partial replacement of soybean meal with mixed plant protein products (RSM, PKM-DDGS) showed no significant effect on the growth performance of pigs during the entire experimental period (p > 0.05). However, a decreasing ADG (p = 0.0837) and ADFI (p = 0.0779) were observed during weeks 0-5, while an increasing FCR was noted during weeks 10-15 (p = 0.0835) and the overall period. Furthermore, the replacement of soybean meal with mixed plant protein products (RSM-PKM-DDGS) showed no linear or quadratic effects on the digestibility of dry matter (DM), nitrogen (N), energy (E), fecal scores, or meat quality.

Conclusion

This suggests that mixed plant protein products (RSM, PKM, and DDGS) can effectively replace soybean meal as the primary protein source, providing comparable outcomes while potentially reducing feed costs.

Lactobacilli-Based Pro and Postbiotic Efficacy Are Also Influenced by Other Factors Than Dietary Challenging Conditions

The present study aimed to confirm the previously reported 'recovery' effect to a challenging diet (CD) of a Lactobacilli-based probiotic (Pro) and its derived postbiotic (Post) in broilers. Identical diet compositions were used, and observations were extended to a second CD diet. A completely randomised block design of 2 × 3 treatment groups with two CDs and three additive conditions (Control, Pro, Post) was used. One additional group received a standard diet (SD). The study involved 1600 one-day-old Ross 308 male broilers. All diets, fed from d1 to 35, were formulated to contain identical nutrients levels, with CDs formulated to be greater than SD in nonstarch polysaccharides using rye and barley (Rye CD) or dry distiller grains with soluble, sunflower and rapeseed meal (DDGS CD). Growth performance parameters, footpad lesions (FPL) score and plasma Ca, P and uric acid concentrations were measured. Compared to SD, birds fed Rye CD and DDGS CD had a higher 1-35 days feed conversion ratio (+3.4 and +4.1%, respectively), due to a higher feed intake for Rye CD (+2.9%) and a lower body weight for DDGS CD (-4.1%). An effect of additive was restricted to Rye CD where Post depressed BW at d28 and d35 (-3.7 and -2.4%, respectively). Compared to Rye CD, DDGS CD lowered plasma Ca/P at d21 (-9.0%) and d35 (-8.1%) and uric acid at d21 (-26%). Pro increased plasma Ca in Rye CD at d21 (+12%) and Post decreased plasma uric acid in DDGS CD at d35 (-25%). All other plasma parameters were not affected. The previously observed recovery effect of a commercial probiotic and postbiotic were not reproducible under highly similar growth conditions, which suggests that both may have specific physiological effects which are only expressed under specific circumstances.

Using a blend of oilseed meals in the diets of Nile tilapia (Oreochromis niloticus): effects on the growth performance, feed utilization, intestinal health, growth, and metabolic-related genes

In this study, Nile tilapia were fed a blend of oilseed meals (BOM) that includes cottonseed meal (CSM), linseed meal (LSM), sesame meal (SSM), and sunflower meal (SFM) at a ratio of 1 CSM: 1 LSM: 1 SSM: 1 SFM. Six diets were formulated where the first diet included FM and SBM as protein sources and considered the positive control diet (FM). Another five FM-free diets were formulated, where SBM was substituted with BOM and included at 0, 100, 200, 300, and 400 g/kg diet. After 90 days, the FBW, WG, and PER were markedly increased while FCR decreased by FM-based diet and BOM at 0, 100, or 200 g/kg compared to fish-fed BOM at 300, and 400 g/kg (P < 0.05). The groups treated with BOM at 100-200 g/kg demonstrated considerable impairments, followed by those treated with BOM at 300 g/kg. Furthermore, fish given BOM at 400 g/kg had significantly less intestinal histological characteristics than the other groups. The relative expression of the IGF-1, GHR1, FABP, and CCK genes were downregulated in tilapia-fed BOM at 200, 300, and 400 g/kg compared to fish-fed FM-based diet (P < 0.05). The relative cost of feed per kg fish gain showed 4.42, 7.11, 8.14, 10.32, and 8.10% reduction rates in fish-fed SBM, or BOM at 100, 200, 300, and 400 g/kg. In conclusion, dietary BOM can be incorporated in Nile tilapia diets at up to 200 g/kg without affecting growth performance or feed utilisation. High inclusion levels (300 and 400 g/kg) may impair growth performance and feed utilisation by disrupting intestinal histological characteristics and reducing expression of growth and metabolic genes (GHR1, IGF-1, FABP, and CCK) in the liver.

Microbiota but not immune modulation by a pro- and postbiotic was associated with the diet-additive interaction in broilers

This study investigated the diet-additive interactions of a Lactobacilli-based probiotic (Pro) and postbiotic (Post) on immune parameters and cecal microbiota composition, with subsequent effects on the metabolome in broilers. A completely randomized block design was employed with 2 diets [standard (SD), and challenge (CD)] and 3 additive conditions (Control, Pro, Post) involving 1,368 one-day-old male Ross 308 broilers equally distributed among 36 pens in a 42 d study. Diets were formulated to contain identical nutrient levels, with CD higher than SD in non-starch polysaccharide content by including rye and barley. Total non-specific serum Ig A, M and G concentrations were determined weekly from d14 to 35. Following vaccination, titres of specific antibodies binding Newcastle disease virus (NDV) and infectious bursal disease virus (IBDV) were measured. Microbiota composition was analyzed by 16S rRNA gene sequencing at d14 and 35, and α- and β-diversity indexes (Observed, Chao1, Bray, Jaccard) were calculated. Cecal short-chain fatty acids and the semi-polar metabolome were determined in the Control SD and all CD groups at d35. At d35, a diet-additive interaction was observed on cecal microbiota composition. Within SD, Pro and Post did not affect operational taxonomic units (OTU) abundance (adjusted-P > 0.05) and diversity indexes (P > 0.05). Within CD, Pro and Post affected the relative abundances of 37 and 44 OTUs, respectively (adjusted-P < 0.05), with Post but not Pro affecting β-diversity indexes (P = 0.041 and 0.064 for Bray and Jaccard, respectively). Within CD, Post increased cecal acetate (21%; P = 0.007) and butyrate (41%; P = 0.002) concentration and affected the concentration of 2 metabolites (adjusted-P < 0.05), while Pro affected 240 metabolites (adjusted-P < 0.05). No diet-additive interactions were observed on serum Ig (P > 0.05), except for IgM at d14 (P = 0.004). Diet composition, but not the additives, affected immune status parameters. The Pro and Post affected cecal microbiota composition only under dietary challenging conditions as previously reported for growth.

Opinion Piece: New Plant-Based Food Products Between Technology and Physiology

The rapid growth of product sectors for plant-based meat and dairy alternatives has raised significant scientific interest in their nutritional and ecological benefits. Here, it outlines the fractionation of plant-based raw materials and describes the technologies applied in the production of meat and dairy substitutes. Moreover, the study describes the effects of these new products on human nutrient supply and metabolic responses. Examples of meat-like products produced by extrusion technology and dairy alternatives are provided, addressing production challenges and the effects of processing on nutrient digestibility and bioavailability. In contrast to animal-based products, plant-based protein ingredients can contain many compounds produced by plants for defense or symbiotic interactions, such as lectins, phytates, and a wide range of secondary metabolites. The intake of these compounds as part of a plant-based diet can influence the digestion, bioaccessibility, and bioavailability of essential nutrients such as minerals and trace elements but also of amino acids. This is a critical factor, especially in regions with limited plant species for human consumption and inadequate technologies to eliminate these compounds. To fully understand these impacts and ensure that plant-based diets meet human nutritional needs, well-controlled human studies are needed.

Sunflower Meal Valorization through Enzyme-Aided Fractionation and the Production of Emerging Prebiotics

Recently, there has been a burgeoning interest in harnessing the potential of biomass and industry byproducts for the development of novel products and materials. In particular, this study explored the efficient valorization of sunflower meal (SFM), an underutilized byproduct of the oil extraction industry, usually discarded or used as low-value animal feed through enzyme-aided fractionation, specifically targeting the extraction and conversion of its abundant carbohydrate component, xylan, into emerging prebiotic compounds-xylo-oligosaccharides (XOSs)-which are recognized as promotors of a healthy gut microbiome and overall human wellbeing. An enzymatic treatment using Alcalase® 2.4 L was implemented for facilitating the recovery of a highly pure hemicellulosic fraction (92.2% carbohydrates) rich in β-(1→4)-linked xylose residues with arabinose and glucuronic acid substitutions (DP-xylan). A further enzymatic treatment of this substrate, using ROHALASE® SEP-VISCO under optimized conditions (70 °C, pH 6, 0.005% v/v enzyme concentration), produced 52.3% of XOSs with a polymerization degree (DP) less than 20 after two hours. Further analyses demonstrated that the majority of the obtained product had a DP less than 6, predominantly consisting of di- and trisaccharides (XOS2 and XOS3) without the significant generation of xylose. These findings highlight the significant potential of SFM for the generation of valuable prebiotic compounds in a sustainable manner.

Fatty Acids and Volatile Flavor Components of Adipose Tissue from Local Tibetan Sheep in Qinghai with Dietary Supplementation of Palm Kernel Meal (PKM)

Substituting traditional protein feed with palm kernel meal (PKM) in the diet of Tibetan sheep can be a cost-effective feeding strategy. To determine the impact of PKM on flavor development in different adipose tissues of Tibetan sheep, subjects were fed with 15% and 18% of PKM, while the control group received no PKM. The fatty acids and volatile compounds in the samples were then analyzed by GC-MS and HS-GC-IMS. Adding PKM to the diet significantly increased the C12:0, C14:0, C16:0 and C18:1N9 content in adipose tissues compared with the control, and most of these were associated with flavor formation (p < 0.05). The flavor compounds in the adipose tissues predominantly consisted of alcohols, ketones, acids and aldehydes. In particular, including PKM in the diet increased the proportion of ketones but decreased the proportion of alcohols, acids and aldehydes in subcutaneous and tail fat. Specifically, the proportion of acetone, acetoin monomer, 2,3-butanedione, 2-butanone monomer, 2-methyl-2-propanol, 2-methyl-2-propanol and methyl acetate increased significantly in the subcutaneous and tail fat (p < 0.05), while that of ethanol, 1-propanol monomer, butanol monomer, acetic acid monomer and acetic acid monomer decreased. Intermuscular fat exhibited variable results, mainly because the addition of PKM resulted in higher proportions of alcohols, including ethanol, 1-propanol and butanol monomer, especially at 15% PKM. In summary, the addition of PKM improved the flavor of Tibetan sheep fat and increased the amount of favorable volatile flavor compounds. This study can serve as reference for understanding the effects of dietary PKM on the adipose tissue flavor profile of Tibetan sheep.

The impact of replacing corn with elephant grass (Pennisetum purpureum) on growth performance, serum parameters, carcass traits, and nutrient digestibility in geese

This study investigated the effects of partially replacing corn with elephant grass dry matter (air drass) on growth performance, serum parameters, carcass traits, and nutrient digestibility in geese. A total of 360 one-day-old Hortobágyi geese were randomly divided into three groups: control (basic diet), 12 % elephant grass, and 24 % elephant grass. The geese were raised for 70 days. The results showed that compared to the control, 12 % elephant grass had no adverse effects on final body weight, feed/gain ratio, mortality, serum liver and kidney function markers. However, 24 % elephant grass significantly reduced the final body weight (P < 0.001) and feed/gain ratio (P = 0.026) compared to the control group. Both experiment groups had decreased serum aspartate aminotransferase (P < 0.001), alanine aminotransferase (P < 0.001), alkaline phosphatase (P < 0.001), triglycerides (P < 0.001), and total cholesterol (P < 0.001). The addition of 12 % and 24 % elephant grass reduced abdominal fat (P = 0.002), but it had no significant effect on slaughter rate, half-bore rate, full-bore rate, breast muscle rate and leg muscle rate. For nutrient digestibility, 12 % elephant grass improved neutral detergent fiber digestibility compared to the control group (P = 0.026). The 24 % grass group had reduced Ca absorption (P = 0.020). Overall, the findings suggest that partially replacing corn with 12 % elephant grass in goose diet can maintain growth performance and carcass traits.It also has no negative effect on nutrient digestibility while improving serum parameters.

Feeding sunflower meal with pullets and laying hens even at a 30% inclusion rate does not impair the ileal digestibility of most amino acids

The use of locally available protein sources in poultry nutrition is challenging for feed manufacturers and farmers. Sunflower meal (SFM) is available in high quantities in several European countries and could be used as a poultry feedstuff at higher inclusion rates. However, its maximum inclusion rate in the diets of different poultry species and age categories is unknown. Pullets and laying hens can probably tolerate higher amounts of SFM, but only limited information is available on these poultry groups. Therefore, a digestibility trial was carried out with 8-week-old layer type pullets and 50-week-old laying hens. Beside a basal diet, SFM was fed at 10, 20 and 30% inclusion rates. Feeding SFM significantly improved the digestibility of essential amino acids (AA) of threonine, valine, lysine, tyrosine, glycine, aspartic acid, and arginine in the pullet diets. No such improvement was found in laying hens. Only the absorption of the two branch-chain AAs, leucin (pullets) and isoleucine (hens), declined due to SFM. The AA digestibility of the SFM itself was also calculated by linear regression. The coefficients were, in all cases, higher in hens than in pullets. Comparing the measured digestibility coefficients of SFM with table values, it can be concluded that high variance exists because of the differences in the methodology and the test animals in the digestibility trials. From the present trial, it can be concluded that SFM can entirely replace extracted soybean meal in pullet and layer diets, without negative effects on the protein digestion of birds.

Red Vetchling (Lathyrus cicera L.), a Promising Crop for the Sustainable Replacement of Soybean Meal and Reducing the Carbon Footprint of European Aquafeeds

In fish diets, soybean meal (SBM) is still positioned as the most widely used alternative to replace fishmeal. Red vetchling (Lathyrus cicera), a crop locally produced in Europe, is here evaluated as a substitute for SBM. Rainbow trout (Oncorhynchus mykiss) juveniles (10.34 ± 0.04 g) were fed for 90 days. Six experimental diets replacing the SBM content at 0, 8, 16, 33, 66, and 100% (Named Control, T8, T16, T33, T66, and T100) were tested. Growth performance and fish fillet amino acid composition were only significantly reduced in fish fed the T100 diet. Histopathological analysis showed that no major alterations were observed in the intestine, while T100 fish had a higher density of pyknotic nuclei in the hepatocytes than the Control, but similar hepatocyte surface coverage. Finally, postprandial levels of glucose and triglycerides in blood plasma decreased when red vetchling content was increased, but was only not fully restored after 24 h in the case of glucose in T66 and T100 fish. According to these results, red vetchling meal can replace up to 66% of the SBM without a negative effect on fish growth or physiology, representing a good alternative raw material for reducing European aquaculture's dependency on SBM imports and the carbon footprint of aquafeeds.

Effects of pretreating wheat middlings and sunflower meal with fiber degrading enzymes on components solubilization and utilization in broiler chickens

Pretreating fibrous feedstuffs with exogenous enzymes may improve their utilization in broiler chickens. Pretreatment of wheat middlings (WM) and sunflower meal (SM) with fiber degrading enzymes (FDE) was investigated for 1) in vitro solubilization of crude protein (CP) and fiber-degrading (experiment 1), and 2) apparent retention (AR) of CP, neutral detergent fiber (NDF), nitrogen corrected apparent metabolizable energy (AMEn), as well as the concentration of ceca digesta metabolites in broiler chickens (experiment 2). In experiment 1, WM was pretreated with FDE and SM with FDE ± protease and incubated in a shaker for 24 or 48 h at 40°C and 200 rpm. Samples were centrifuged, and the supernatant used for assay of sugars and organic acids and pellet processed for determination of apparent disappearance (AD) of dry matter (DM), fiber, and CP solubilization. In experiment 2, WM and SM were pretreated with FDE for 24 h, oven-dried, and incorporated in iso-caloric and iso-nitrogenous experimental diets. Diets were: 1) a corn-soybean meal positive control (PC); 2) PC plus untreated WM and SM (negative control, NC), and diets 3, 4, 5, and 6 test diets, in which the untreated WM and SM in NC were replaced with pretreated WM and SM at 25% (N25), 50% (N50), 75% (N75), and 100% (N100), respectively. Diets were prepared in mash form in two phases (starter, days 0 to 21 and finisher, days 22 to 42) and had TiO2 (0.3%) as an indigestible marker. A total of 288 Ross708 d-old male broiler chicks were placed in cages based on body weights (6 birds/cage) and allocated diets (n = 8). Birds had free access to feed and water. Samples of excreta for AR and AMEn, and of ceca digesta for the concentration of short-chain fatty acids (SCFA) were collected at the end of each phase. Pretreatment with FDE increased (P < 0.001) solubilization of CP, AD of NDF, and release of sugars and organic acids in the supernatant. The mixture of FDE and protease further increased (P < 0.001) CP solubilization in SM. Feeding pretreated WM and SM had a linear response (P ≤ 0.038) on AMEn, and gross energy (GE) (day 21) and a quadratic response (P < 0.05) on AR of components and AMEn (day 42) and concentration of total SCFA on day 42. On day 42, N25 and N50 had higher AR of DM, CP, NDF, and GE than N75 and N100. In conclusion, pretreatment of WM and SM with enzymes increased CP and fiber degradation. Incorporating moderate amounts (N25 and N50) of pretreated WM and SM in a corn-soybean meal diet fed to broiler chickens improved nutrient and energy utilization.

Carbohydrate-active enzymes in animal feed

Considering an ever-growing global population, which hit 8 billion people in the fall of 2022, it is essential to find solutions to avoid the competition between human food and animal feed for croplands. Agricultural co-products have become important components of the circular economy with their use in animal feed. Their implementation was made possible by the addition of exogenous enzymes in the diet, especially carbohydrate-active enzymes (CAZymes). In this review, we describe the diversity and versatility of microbial CAZymes targeting non-starch polysaccharides to improve the nutritional potential of diets containing cereals and protein meals. We focused our attention on cellulases, hemicellulases, pectinases which were often found to be crucial in vivo. We also highlight the performance and health benefits brought by the exogenous addition of enzymatic cocktails containing CAZymes in the diets of monogastric animals. Taking the example of the well-studied commercial cocktail Rovabio™, we discuss the evolution, constraints and future challenges faced by feed enzymes suppliers. We hope that this review will promote the use and development of enzyme solutions for industries to sustainably feed humans in the future.

Advances in process design, techno-economic assessment and environmental aspects for hydrothermal pretreatment in the fractionation of biomass under biorefinery concept

The development and sustainability of second-generation biorefineries are essential for the production of high added value compounds and biofuels and their application at the industrial level. Pretreatment is one of the most critical stages in biomass processing. In this specific case, hydrothermal pretreatments (liquid hot water [LHW] and steam explosion [SE]) are considered the most promising process for the fractionation, hydrolysis and structural modifications of biomass. This review focuses on architecture of the plant cell wall and composition, fundamentals of hydrothermal pretreatment, process design integration, the techno-economic parameters of the solubilization of lignocellulosic biomass (LCB) focused on the operational costs for large-scale process implementation and the global manufacturing cost. In addition, profitability indicators are evaluated between the value-added products generated during hydrothermal pretreatment, advocating a biorefinery implementation in a circular economy framework. In addition, this review includes an analysis of environmental aspects of sustainability involved in hydrothermal pretreatments.

Feeding dietary fermentable fiber improved fecal microbial composition and increased acetic acid production in a nursery pig model

The objective of this study was to determine the fermentable fiber (FF) content of several common fibrous ingredients fed to nursery pigs, and then evaluate the effect of dietary FF level on growth performance and fecal microbial composition. In experiment 1, 54 nursery pigs were randomly allotted to be fed nine diets with six replicate pigs per diet. Dietary treatments included a corn-soybean meal basal diet and eight test diets based on a mixture of the corn-soybean meal diet and corn distillers dried grains with solubles, sunflower meal, oat bran, wheat bran, corn bran, sugar beet pulp (SBP), apple pomace (AP) or soybean hulls (SH). In experiment 2, 180 nursery pigs were housed in 30 pens (six pigs per pen) and randomly allotted to be fed five diets with different FF to total dietary fiber (TDF) ratios, which were 0.52, 0.55, 0.58, 0.61, and 0.64, respectively. Results showed that the FF content in SBP, AP, and SH was greater (P < 0.01) than that in other ingredients. Water binding capacity of fibrous ingredients was positively correlated (P < 0.05) to the digestibility of TDF, acid detergent fiber, and non-starch polysaccharides in test ingredients. Pigs fed the SBP, AP and SH diets had greater (P < 0.05) fecal acetic acid and total short-chain fatty acids (SCFAs) concentrations compared with pigs fed other diets. Fecal acetic acid and total SCFAs concentrations were positively correlated (P < 0.05) with FF content in experimental diets. Average daily weight gain and average daily feed intake of pigs quadratically increased (P < 0.01) as the ratios of FF to TDF increased. Pigs in FF64% group showed higher (P < 0.05) ACE index and fecal acetic acid concentration compared with pigs fed the dietary FF/TDF ratio of 0.52 to 0.61. Compared with the classification system of soluble dietary fiber and insoluble dietary fiber, FF could better describe the mechanism by which dietary fiber has beneficial effects on pig gut health.

Simultaneous Analysis of Free/Combined Phytosterols in Rapeseed and Their Dynamic Changes during Microwave Pretreatment and Oil Processing

Here, a simple, efficient, and rapid solid phase extraction-gas chromatography (SPE–GC) method was developed for the simultaneous analysis of free/combined phytosterols in rapeseed and their dynamic changes during microwave pretreatment and oil processing. First, by comparing different methods for extracting free/combined phytosterols from rapeseed and rapeseed cake, the Folch method was considered to be the optimal method and was selected in subsequent experiments. Subsequently, the extraction method was validated by determining the recoveries of standards (brassinosterol, campesterol, β-sitosterol and cholesteryl oleate) spiked in rapeseed and rapeseed oil samples, and the recoveries were in the range from 82.7% to 104.5% and 83.8% to 116.3%, respectively. The established method was applied to study the dynamic changes of the form and content of phytosterols in rapeseed and its products (rapeseed oil and cake) during rapeseed microwave pretreatment and the oil production process. Additionally, the results showed that more than 55% of the free/combined phytosterols in rapeseed were transferred to rapeseed oil during the oil processing, and this proportion will increase after microwave pretreatment of rapeseed. This work will provide analytical methods and data support for a comprehensive understanding of phytosterols in rapeseed and its products during oil processing.