Potato Protein Research Articles

Exploring the potential of high hydrostatic pressure and ionic polysaccharides in improving interfacial stability of sweet potato protein hydrolysate emulsions

SummaryThis study aims to explore the potential of high hydrostatic pressure (HHP, 300–500 MPa) and ionic polysaccharides (sodium alginate, SA; chitosan, CH) in improving interfacial stability of sweet potato protein hydrolysate (SPPH) emulsions. HHP markedly improved emulsifying performance of SPPH with SA and CH at different concentrations (0.02% and 0.06%, w/v) and enhanced the apparent viscosities of their emulsions. SPPH‐CH0.02% at 400 MPa showed the highest emulsifying stability index (ESI, 255.96 min) and zeta potential absolute value (54.13 mV), and its emulsion exhibited the highest adsorbed peptide and CH at interface (31.72% and 1.51%, respectively) and oxygen radical absorbance capacity (ORAC) value of interfacial layer (264.56 μg TE mL−1). Additionally, multiple potential antioxidant peptides were obtained from interfacial layer of emulsion stabilised with SPPH‐CH0.02% at 400 MPa through LC‐MS/MS, and the relationship between their structure and emulsion stability was analysed. Therefore, HHP has great application potential in production of SPPH‐CH emulsion with enhanced stability.

Extractability and chromatographic separation of proteins from potato (Solanum tuberosum L.) trimmings

By-products from the potato processing industry, like potato trimmings, are sustainable sources of proteins. Here, a size-exclusion high performance liquid chromatography (SE-HPLC) method was applied to simultaneously determine the extractability and aggregation state of proteins from three batches of potato trimmings of different cultivars. Obtained SE-HPLC profiles allowed distinguishing between the patatin and protease inhibitor fractions of potato proteins. Moreover, only 75% of the crude proteins could be extracted in phosphate buffer containing sodium dodecyl sulfate and a reducing agent, indicating the presence of physical extraction barriers. Ball milling for 5 min significantly increased protein extractability, but prolonged treatment resulted in aggregation of native patatin and a reduced protein extractability. Microwave-dried trimmings had a lower protein extractability than freeze-dried trimmings. In future research, the SE-HPLC method can be used to examine changes in potato protein (fractions) as a result of processing.

Changes in potato peptide bioactivity after gastrointestinal digestion. An in silico and in vitro study of different patatin-rich potato protein isolate matrices

Potato protein has gained attention as a promising protein source, because of its amino acid profile and technological functionality; however, little is reported about its nutritional properties as a function of processing history. In this work, the digesta of the four potato protein matrices (suspension, foam, gel, and heated foam) were analyzed by LC-MS/MS and their bioactivity evaluated in vitro and in silico.Different treatments significantly influenced digestion efficiency and peptide distribution. Heat treatment enhanced the hydrolysis, which led to distinct peptide patterns and distributions compared to unheated proteins. Heated foams showed smallest concentration of residual protein in the intestinal stage, and the highest resistance to digestion. Peptides obtained after digestion exhibited a range of potential health benefits in silico, namely, antimicrobial, antihypertensive, and antioxidant activities. All intestinal digesta showed in vitro DPPH radical scavenging and ACE-inhibitory activity.

Screening for Metal-Chelating Activity in Potato Protein Hydrolysates Using Surface Plasmon Resonance and Peptidomics.

Metal-catalyzed lipid oxidation is a major factor in food waste, as it reduces shelf life. Addressing this issue, our study investigates the potential of hydrolysates derived from potato protein, a by-product of potato starch production, as metal-chelating antioxidants. Through sequential enzymatic hydrolysis using alcalase or trypsin combined with Flavourzyme, we produced various hydrolysates, which were then fractionated using ultrafiltration. Using a combination of peptidomics and bioinformatics, we predicted the presence of metal-chelating and free radical-scavenging peptides across all hydrolysate fractions, with a trend indicating a higher content of antioxidant peptides in lower molecular weight fractions. To validate these predictions, we utilized surface plasmon resonance (SPR) and a 9-day emulsion storage experiment. While SPR demonstrated potential in identifying antioxidant activity, it faced challenges in differentiating between hydrolysate fractions due to significant standard errors. In the storage experiment, all hydrolysates showed lipid oxidation inhibition, though not as effectively as ethylenediaminetetraacetic acid (EDTA). Remarkably, one fraction (AF13) was not significantly different (p < 0.05) from EDTA in suppressing hexanal formation. These results highlight SPR and peptidomics/bioinformatics as promising yet limited methods for antioxidant screening. Importantly, this study reveals the potential of potato protein hydrolysates as antioxidants in food products, warranting further research.

The WY Domain of an RxLr Effector Drives Interactions with a Host Target Phosphatase to Mimic Host Regulatory Proteins and Promote Phytophthora infestans Infection.

Plant pathogens manipulate the cellular environment of the host to facilitate infection and colonization that often lead to plant diseases. To accomplish this, many specialized pathogens secrete virulence proteins called effectors into the host cell, which subvert processes such as immune signaling, gene transcription, and host metabolism. Phytophthora infestans, the causative agent of potato late blight, employs an expanded repertoire of RxLR effectors with WY domains to manipulate the host through direct interaction with protein targets. However, our understanding of the molecular mechanisms underlying the interactions between WY effectors and their host targets remains limited. In this study, we performed a structural and biophysical characterization of the P. infestans WY effector Pi04314 in complex with the potato Protein Phosphatase 1-c (PP1c). We elucidate how Pi04314 uses a WY domain and a specialized C-terminal loop carrying a KVxF motif that interact with conserved surfaces on PP1c, known to be used by host regulatory proteins for guiding function. Through biophysical and in planta analyses, we demonstrate that Pi04314 WY or KVxF mutants lose their ability to bind PP1c. The loss of PP1c binding correlates with changes in PP1c nucleolar localization and a decrease in lesion size in plant infection assays. This study provides insights into the manipulation of plant hosts by pathogens, revealing how effectors exploit key regulatory interfaces in host proteins to modify their function and facilitate disease. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.

Effects of different protein sources in low-phosphorus diets on calculated basal endogenous loss of phosphorus by growing pigs

The objective of this experiment was to test the hypothesis that the basal endogenous loss (BEL) of P from pigs fed a diet containing spray dried plasma, casein, or potato protein concentrate is not different from that of pigs fed a diet containing gelatin. Forty pigs (body weight: 19.34 kg; SD = 0.80) were housed individually in metabolism crates and allotted to four low-P diets using a completely randomized block design with two blocks of 20 pigs and five pigs per diet in each block. Diets were based on cornstarch and sucrose and contained 200 g/kg gelatin, 200 g/kg spray dried plasma, 185 g/kg casein, or 200 g/kg potato protein concentrate. With the exception of Ca and P, diets were formulated to meet requirements of all nutrients. Feces and urine samples were collected for 4 d following a 5-d adaptation period. Fecal samples were dried and ground, and fecal and urine samples were analyzed for P. Data were analyzed using a model that included diet as fixed effect and block as random effect. Results indicated that feed intake and fecal excretion of dry matter were greater (P < 0.05) in pigs fed diets containing spray dried plasma, casein, or potato protein concentrate compared with pigs fed the gelatin diet, with pigs fed potato protein concentrate having the greatest (P < 0.05) excretion. The apparent total tract digestibility (ATTD) of dry matter was least (P < 0.001) in pigs fed the diet containing potato protein concentrate, but there were no differences among gelatin, spray dried plasma, and casein diets. The ATTD of P was greater (P < 0.001) in pigs fed diets containing spray dried plasma or casein compared with pigs fed gelatin or potato protein concentrate diets. The BEL of P was not different between the gelatin and casein diets (i.e., 176 and 234 mg/kg dry matter intake), but pigs fed diets containing spray dried plasma or potato protein concentrate had greater (P < 0.001) BEL of P (i.e., 338 and 374 mg/kg dry matter intake) compared with pigs fed gelatin or casein diets. In conclusion, the BEL of P was greater if calculated from diets containing spray dried plasma or potato protein concentrate compared with gelatin. However, casein may be an alternative to gelatin to estimate the BEL of P because casein provides a greater amount of P compared with gelatin, which compensates for the deficient level of P in gelatin, but does not affect the BEL of P.

High pressure and heat-induced potato protein aggregates: A comparison of aggregation kinetics, structure modifications, and protein interactions.

Understanding the techno-functional properties of underutilized plant-based proteins, such as potato proteins, is essential in the context of the development of alternative proteins and plant-based foods. In this study, the aggregation kinetics of patatin-rich dispersions at two concentrations (1% and 4% w/w) and pH levels (6 and 7) were evaluated and compared under two physical processes: heat treatment (45 °C, 50 °C, 55 °C) and high hydrostatic pressure (400 MPa, 600 MPa). Distinct patterns in patatin aggregation were observed based on the processing and physicochemical conditions. Under all processing conditions, larger aggregates were formed at pH 6. Heat treatment led to either a slow or rapid gradual increase in aggregate size at the different pH and protein concentrations, while high-pressure-generated nanoaggregates displayed pH and pressure-level dependent kinetic behaviors. Some micro, sub-micron and nanoaggregates were then selected and characterized in terms of denaturation yield, molecular structure, and protein interactions. High-pressure treatment induced a significant reduction in protein intrinsic fluorescence intensity suggesting irreversible partial protein unfolding, irrespective of pressure or pH. The highest pressure level (600 MPa) led to significantly higher denaturation, regardless of pH. Similar trends in secondary structure modifications were observed for the different treatment conditions and were characterized by an increase in β-sheet content and a reduction in α-helices. The structural changes in the high pressure-treated samples were particularly influenced by pH. This study provides a deeper understanding of potato protein behavior under different treatment conditions, which may contribute to the design of novel plant-based protein nanostructures.

Lactococcus cell envelope proteases enable lactococcal growth in minimal growth media supplemented with high molecular weight proteins of plant and animal origin.

Lactic acid bacteria (LAB) have evolved into fastidious microorganisms that require amino acids from environmental sources. Some LAB have cell envelope proteases (CEPs) that drive the proteolysis of high molecular weight proteins like casein in milk. CEP activity is typically studied using casein as the predominant substrate, even though CEPs can hydrolyze other protein sources. Plant protein hydrolysis by LAB has rarely been connected to the activity of specific CEPs. This study aims to show the activity of individual CEPs using LAB growth in a minimal growth medium supplemented with high molecular weight casein or potato proteins. Using Lactococcus cremoris MG1363 as isogenic background to express CEPs, we demonstrate that CEP activity is directly related to growth in the protein-supplemented minimal growth media. Proteolysis is analyzed based on the amino acid release, allowing a comparison of CEP activities and analysis of amino acid utilization by L. cremoris MG1363. This approach provides a basis to analyze CEP activity on plant-based protein substrates as casein alternatives and to compare activity of CEP homologs.

Plant-based bigels for delivery of bioactive compounds: Influence of hydrogel:oleogel ratio and protein concentration on their physicochemical properties

Bigels are a class of soft matter systems with high potential in food industry as fortified ingredient replacers or food analogs. The aim of this work was to develop plant-based bigels using potato protein-based hydrogel and candelilla wax-based oleogel. The potato protein concentration and hydrogel:oleogel ratio effects on bigels production was assessed in terms of textural and rheological properties. The incorporation of curcumin and its bioaccessibility after in vitro digestion was also evaluated. All samples presented an oleogel-in-hydrogel structure arrangement. Increasing the protein concentration led to increased hardness and G*, improving the structure and consistency of bigels. The increase of oleogel fraction altered the distribution of oleogel droplets in the hydrogel matrix, affecting the hardness and the consistency of bigels. Overall, the increase of oleogel fraction and protein concentration allowed forming bigels with stronger mechanical properties and higher thermal resistance. The bigel showed a curcumin's bioaccessibility of 16.3 % and a curcumin's stability of 43.8 %, suggesting that this type of structures is promising for the delivery of bioactive compounds at the colon or for slow release of bioactive compounds. Overall, the results showed the possibility to develop potato protein-based bigels with interesting mechanical, rheological and thermal properties by changing the protein concentration and hydrogel:oleogel ratio, expanding the application of bigels in novel food products with high nutritional value and protein content, namely plant-based products.

Modulating the textural and structural characteristics of curdlan-potato protein gel with different concentrations

The use of protein-polysaccharide complexes as fat substitutes to reduce fat and maintain fat functionality has received much attention in the food industry. In the present study, complex gels were developed using curdlan (CR) and potato protein (PP) for the potential of development as a solid fat analog. The effect of PP concentrations (1–6%) on the texture, water-holding capacity, freeze-thaw stability, and microstructure of the resultant curdlan-potato protein (CP) gel was investigated. The results showed that the texture properties of the gel with 3% PP were the most similar to those of pork backfat. The addition of PP contents had a pronounced enhancement in the water-holding capacity, and freeze-thaw stability tended to increase and subsequently decrease after 4% PP (p < 0.05). The low-field NMR confirmed the addition of PP improved the migration and tighter binding of water. The elastic modulus of CP gels increased initially before declining, reaching a maximum at a protein concentration of 3% and a minimum at 5%. The microstructure demonstrated a gradual aggregation and phase separation process of PP and CR, resulting in a strengthened skeleton network. These findings provide a reference for the development of a novel non-animal fat analog in the food industry.

Control of plant-based biopolymer composite gel texture: Combining potato proteins with different high acyl-low acyl gellan gum ratios

The impact of blending different kinds of gellan gum (GG) on the textural attributes of potato protein-based biopolymer composites was studied. The total potato protein concentration (10 wt%) and gellan gum concentration (3 wt%) of the composite gels was fixed but the ratio of HAGG (forms soft and elastic gel) to LAGG (forms hard and brittle gel) was varied (100:0 to 0:100). During cooling, HAGG set at a higher temperature than LAGG, due to differences in steric hindrance effects. As the LAGG content increased, the shear modulus, Young's modulus, and brittleness of the gels increased, while their water holding capacity decreased. There were no major differences in the nature of the molecular interactions between the proteins in composite gels formulated using different gellan gum ratios. The addition of an antifoaming agent significantly reduced the variability in the textural attributes of the gels and increased their gel strength, which was attributed to its ability to suppress bubble formation. Overall, our results suggest that the textural attributes of biopolymer composite gels can be controlled by using plant proteins in combination with a pair of polysaccharides with different gelling properties. This knowledge may aid in the formulation of soft solid plant-based foods with more desirable textural attributes, such as meat, seafood, or egg analogs.

Comparison of different protein sources on the phosphorus digestibility of soybean meal for broiler chickens determined using the regression method

A study was conducted to evaluate the P digestibility in soybean meal (SBM) using the regression method with different basal diet that varied in protein sources. The treatments were organized in a 4 × 3 factorial arrangement, where 4 semipurified diets were formulated with varying source of protein (no protein supplement, or added casein, potato protein isolate (PPI), or dried egg albumen (DEA) at 60 g/kg) and 3 dietary levels of SBM (290, 370, or 450 g/kg). The study was a randomized complete block design with 8 replicate cages of 6 birds per cage. The experimental diets were fed from d 19 to 22 posthatching, excreta samples were collected from d 20 to 22, and ileal digesta samples were collected on d 22. Data were analyzed as a 2-way ANOVA using the GLM procedure. The digestibility and total tract utilization of DM, P, Ca, and N were affected by protein source (P < 0.05). Diets with casein presented the highest (P < 0.05) digestibility of N. Increasing SBM level in all dietary protein sources reduced (P < 0.001) the digestibility and total tract utilization of DM. The regression-derived ileal digestibility of P in SBM was 57.8 (SE = 3.78), 63.2 (SE = 5.02), 58.8 (SE = 4.53), and 35.3% (SE = 5.27) for diets without protein supplement, with casein, PPI, or DEA, respectively; the corresponding P retention were 52.2 (SE = 11.09), 83.4 (SE = 14.89), 42.6 (SE = 15.88), and 51.9% (SE = 14.67). The protein source affected (P < 0.05) the slope and intercept of P digestibility in SBM. A comparison of the coefficients using confidence intervals demonstrated that the ileal digestibility of P in SBM determined in diets with DEA was lower (P < 0.05) than the other protein sources, which did not differ from one another. These results indicate that the selection of dietary protein supplements may affect P digestibility assays using the regression method.

Impact of potato trimming acidification on protein characteristics and bacterial community during long-term storage

Potato trimmings are a valuable by-product from potato processing containing both nutritional and functional potato protein. However, to allow delayed processing of trimmings, stabilisation methods should be implemented ensuring food safety and protein quality. In this study, acidification strategies by addition of different concentrations of organic acids i.e. acetic-, lactic- and citric acid were investigated as novel stabilisation methods for potato trimming and compared to natural acidification. Stabilisation was analysed and assessed by a variety of microbial, biochemical and protein characteristics.After 56 days of storage in acidified conditions, no decreases in true protein contents were observed despite changes in the protein molecular weight profile. In terms of food safety, yeast and mould inhibition during storage could solely be achieved by acetic acid addition, while lactic and citric acid could even result in increased unwanted growth. Therefore, acetic acid addition has been proven to be a successful stabilisation strategy.

Molecular Cloning, Expression Analysis, and Functional Analysis of Nine IbSWEETs in Ipomoea batatas (L.) Lam

Sugar Will Eventually be Exported Transporter (SWEET) genes play an important regulatory role in plants’ growth and development, stress response, and sugar metabolism, but there are few reports on the role of SWEET proteins in sweet potato. In this study, nine IbSWEET genes were obtained via PCR amplification from the cDNA of sweet potato. Phylogenetic analysis showed that nine IbSWEETs separately belong to four clades (Clade I~IV) and contain two MtN3/saliva domains or PQ-loop superfamily and six~seven transmembrane domains. Protein interaction prediction showed that seven SWEETs interact with other proteins, and SWEETs interact with each other (SWEET1 and SWEET12; SWEET2 and SWEET17) to form heterodimers. qRT-PCR analysis showed that IbSWEETs were tissue-specific, and IbSWEET1b was highly expressed during root growth and development. In addition to high expression in leaves, IbSWEET15 was also highly expressed during root expansion, and IbSWEET7, 10a, 10b, and 12 showed higher expression in the leaves. The expression of SWEETs showed a significant positive/negative correlation with the content of soluble sugar and starch in storage roots. Under abiotic stress treatment, IbSWEET7 showed a strong response to PEG treatment, while IbSWEET10a, 10b, and 12 responded significantly to 4 °C treatment and, also, at 1 h after ABA, to NaCl treatment. A yeast mutant complementation assay showed that IbSWEET7 had fructose, mannose, and glucose transport activity; IbSWEET15 had glucose transport activity and weaker sucrose transport activity; and all nine IbSWEETs could transport 2-deoxyglucose. These results provide a basis for further elucidating the functions of SWEET genes and promoting molecular breeding in sweet potato.

Multivalent cations modulating microstructure and interactions of potato protein and fungal hyphae in a functional meat analogue

Concentrated Fusarium venenatum biomass commonly known as mycoprotein (MYC), naturally rich in high quality proteins, has been commercially used to fabricate vegan meat analogues by incorporating potato protein (PoP). In this work, we studied the effect of multivalent cations, focusing particularly on essential micronutrients such as calcium (0–100 mM) and ferric ions (0–1.0 mM), on the microstructure of the fungal hyphae (MYC)-PoP composites, as characterized via rheology and microscopic techniques as a function of pH (3.0–7.0), Na+ (0–200 mM) with and without added PoP. A clear dependency of storage modulus (G′) on pH, ionic strength and specific concentrations of Ca2+ and Fe3+ was observed, with Fe3+, PoP concentration and acidic pH having the largest impact. Microscopy across various length scales revealed that PoP coats the hyphae's rough surface and dominates the interactions between the hyphae. G′ responsiveness to NaCl and CaCl2 concentrations indicated that electrostatic interactions between the fungal hyphae and PoP coverage mainly govern texture properties. Interestingly, Fe3+ induced protein-protein aggregation which led to a reduction in G′ of MYC without PoP. However, the effect of Fe3+ was modulated by Ca2+, where increasing concentration of both salts seemed to narrow the rheological (G′) differences between MYC with and without PoP at higher pH. Fe3+ alone significantly increased the G′ of MYC-PoP except at pH 5.0. Thus, a subtle balancing of pH and added levels of calcium is needed to enable iron supplementation with minimal textural effects when formulating mycoprotein-based meat analogues with PoP as protein binding agent.

Impact of heat-set and cold-set gelling polysaccharides on potato protein gelation: Gellan gum, agar, and methylcellulose

The plant-based meat market is growing due to concerns about the sustainability of the modern food system. Plant-based meats are often constructed from blends of food biopolymers, such as plant proteins and polysaccharides. This study characterizes the thermal setting properties of potato protein (10%) and polysaccharide (2 wt%) mixtures containing polysaccharides with different reversible gelling behaviors: agar (cold set); gellan gum (cold set); or methyl cellulose (heat set). Each sample was heated above the thermal denaturation temperature of the potato proteins to promote protein unfolding, aggregation, and network formation. The addition of the polysaccharides tended to increase the complex shear modulus of the biopolymer blends before heating but increase or decrease it after heating depending on polysaccharide type. The shear modulus and hardness of the gels formed after heating tended to increase after addition of the cold-set polysaccharides but decrease after the addition of the heat-set polysaccharides, especially at refrigerator temperatures. Differential scanning calorimetry data showed that the potato proteins underwent irreversible denaturation after heating for all samples. Zeta-potential analysis showed that the potato proteins and all polysaccharides were negatively charged under the pH conditions used. There was greater water loss during heating for the composite gels containing methyl cellulose, which may have been due to its increase hydrophobicity at high temperatures. Appearance and microstructure analysis showed that phase-separation occurred after mixing the polysaccharides with the potato proteins, which was attributed to a segregation mechanism. The knowledge obtained from this study may help the food industry to optimize protein-polysaccharide blends to create gels with characteristics and structures that can mimic different plant-based meat products.

Exploring the potential of plant-based emulsion gels enriched with β-glucan and potato protein as egg yolk alternatives

This study investigated the microstructure, physicochemical properties, and digestibility of plant-based egg yolk (PBEY) as a potential replacement for real egg yolk (REY). The PBEY consisted of oil-in-water emulsions containing β-carotene and vitamin D in the oil phase and β-glucan and potato proteins in the aqueous phase. The potato proteins were used as natural emulsifiers and gelling agents, the β-carotene was used as a natural yellow pigment, and the β-glucan, β-carotene, and vitamin D were used to improve the nutritional profile. In aqueous solutions, β-glucan was susceptible to aggregation and precipitation. However, it remained stable in PBEY during storage, which was attributed to non-covalent interactions between the potato proteins and β-glucan. β-glucan increased the apparent shear viscosity and shear thinning behavior of the PBEY, which was attributed to its polymeric nature. The thermal gelling properties of the PBEY were also affected by β-glucan addition, with a decrease in gelation temperature and final gel strength, indicating changes in gel structure. The addition of β-glucan also increased the hardness and resilience of the egg analogs, with 2.5 wt% yielding properties like REY in terms of springiness and chewiness. The color matching theory was used to match the color of the PBEY to REY. Optimizing the concentration of β-carotene in the PBEY allowed us to successfully match the yellow color of REY. The presence of β-glucan in the PBEY increased protein hydrolysis during simulated gastric and small intestinal digestion, but it decreased lipid hydrolysis and vitamin D bioaccessibility in the small intestine. This reduced bioaccessibility was attributed to the ability of the polysaccharide to inhibit the digestion of the protein-coated oil droplets. This study provides an improved understanding of how β-glucan affects the properties of nutrient-fortified PBEY. The PBEY developed in this study may be suitable for consumers seeking healthy and sustainable plant-based alternatives to REY. However, further research is required to test the sensory properties.

Antioxidant peptides from alternative sources reduce lipid oxidation in 5% fish oil-in-water emulsions (pH 4) and fish oil-enriched mayonnaise.

Bioinformatics tools were used to predict radical scavenging and metal chelating activities of peptides derived from abundant potato, seaweed, microbial, and spinach proteins. The antioxidant activity was evaluated in 5% oil-in-water emulsions (pH4) and best-performing peptides were tested in mayonnaise and compared with EDTA. Emulsion physical stability was intact. The peptide DDDNLVLPEVYDQD showed the highest protection against oxidation in both emulsions by retarding the formation of oxidation products and depletion of tocopherols during storage, but it was less efficient than EDTA when evaluated in mayonnaise. In low-fat emulsions, formation of hydroperoxides was reduced 4-folds after 5days compared to control. The concentration effect of the peptide was confirmed in mayonnaise at the EDTA equimolar concentration. The second-best performing peptides were NNKWVPCLEFETEHGFVYREHH in emulsion and AGDWLIGDR in mayonnaise. In general, the peptide efficacy was higher in low-fat emulsions. Results demonstrated that peptide negative net charge was important for chelating activity.

123 Effects of Different Protein Sources Containing Highly Digestible Phosphorus on the Basal Endogenous Loss of Phosphorus

Abstract The objective of this experiment was to test the hypothesis that the basal endogenous loss of P from pigs fed a diet containing blood plasma, casein, or potato protein concentrate is not different from that of pigs fed a diet containing gelatin. Pigs (n = 40; body weigh =: 19.34 kg) were housed in metabolism crates and were randomly allotted to four low-P diets containing 20% gelatin, 20% blood plasma, 18.5% casein, or 20% potato protein concentrate. With the exception of Ca and P, diets were formulated to meet the requirements for 11 to 25 kg pigs. Feces and urine samples were collected separately for 4 d following a 5-d adaptation period. Feces samples were dried, ground, and analyzed for Ca and P, and urine samples were also analyzed for Ca and P. Data were analyzed using a model that included diet as fixed effect and replicate as random effect. Results indicated that feed intake and fecal excretion of dry matter were greater (P &amp;lt; 0.05) in pigs fed diets containing blood plasma, casein, and potato protein concentrate compared with pigs fed the gelatin diet, with pigs fed potato protein concentrate having the greatest (P &amp;lt; 0.05) excretion (Table 1). The apparent total tract digestibility of dry matter was least (P &amp;lt; 0.001) in pigs fed the diet containing potato protein concentrate, but there were no differences among gelatin, blood plasma, and casein diets. No differences were observed in the standardized total tract digestibility of P among diets. Basal endogenous loss of P was not different between the gelatin and casein diets, but pigs fed diets containing blood plasma or potato protein concentrate had greater (P &amp;lt; 0.001) basal endogenous loss of P compared with pigs fed gelatin or casein diets. In conclusion, the basal endogenous loss of P was greater in diets containing blood plasma and potato protein concentrate compared with gelatin. However, casein could be an alternative to gelatin to estimate the basal endogenous loss of P because casein provides a greater amount of P compared with gelatin that compensates for the deficient level of P in gelatin, but does not affect values for the basal endogenous loss of P.

Are Growth Performance and Fecal Score in Weaning Pigs Affected by the Inclusion Level of Potato Protein Concentrate and the Enclosed Glycoalkaloids in Iso-Nitrogenous Diets?

Glycoalkaloids (GA) are anti-nutritional factors in standard potato protein concentrate (PPC) fed to piglets. Increasing levels of standard PPC was expected to affect growth performance and fecal score negatively. Seven-hundred-and-twenty pigs (7-30 kg) were fed one of the following four diets within three feeding phases (days 0-13, 13-24, and 24-45): control (CTRL), PPC standard inclusion (PPC-S; 4%, 2%, and 0%), high PPC inclusion (PPC-H; 8%, 3.5%, and 2%), and extremely high PPC inclusion (PPC-EH; 12%, 5%, and 3.5%). During days 0-13, CTRL displayed no difference in growth performance compared with the three experimental groups (PPC-S, PPC-H, and PPC-EH). During days 13-24, PPC-H achieved greater (p < 0.001) average daily feed intake (ADFI) compared to CTRL. During days 24-45, no differences between groups were observed. For the overall experimental period (0-45 days), PPC-H displayed greater average daily gain (ADG) (p = 0.010) and ADFI (p = 0.024) compared to CTRL. The feed conversion ratio (FCR) remained unaffected between the groups for all experimental periods. Increasing levels of PPC and hence GA did not affect the probability of diarrhea. In conclusion, increased standard PPC and hence increased levels of GA in isonitrogenous diets did not negatively affect growth performance nor fecal score in piglets (7-30 kg).