Potato Protein Hydrolysate Research Articles

Sweet potato protein hydrolysates solidified calcium-induced alginate gel for enhancing the encapsulation efficiency and long-term stability of purple sweet potato anthocyanins in beads

Based on the previous research, this work aimed to reveal the effect of sweet potato protein hydrolysates (SPPHs) with different molecular weights (1000, 3000, and 8000 Da) at 0.5 % on the gelation behavior of calcium-induced sodium alginate (SA), and the encapsulation efficiency and storage stability of purple sweet potato anthocyanins (PSPA) in calcium-induced alginate gel beads was determined. Results indicated that SPPHs with a molecular weight of 8000 Da formed hydrogen bonds and other interactions with SA, which strengthened the internal network connections of the gel, significantly enhanced the gel and effectively filled its pores. The highest encapsulation efficiency was achieved at 87.27 %, compared to 61.73 % without SPPHs. Additionally, stored at 37 °C for 21 days after commercial sterilization, the residual concentration of PSPA with SPPHs was 2.50 times higher than that without SPPHs. SPPHs can enhance the encapsulation efficiency of PSPA and retard their release in gel beads.

Potato protein hydrolysate inhibits RANKL-induced osteoclast development by inhibiting osteoclastogenic genes via the NF-κB/MAPKs signaling pathways.

In recent times, there has been growing attention towards exploring the nutritional and functional aspects of potato protein, along with its diverse applications. In the present study, we examined the anti-osteoclast properties of potato protein hydrolysate (PP902) in vitro. Murine macrophages (RAW264.7) were differentiated into osteoclasts by receptor activator of nuclear factor-κB ligand (RANKL), and PP902 was examined for its inhibitory effect. Initially, treatment with PP902 was found to significantly prevent RANKL-induced morphological changes in macrophage cells, as determined by tartrate-resistant acid phosphatase (TRAP) staining analysis. This notion was further supported by F-actin analysis using a confocal microscope. Furthermore, PP902 treatment effectively and dose-dependently down-regulated the expression of RANKL-induced osteoclastogenic marker genes, including TRAP, CTR, RANK, NFATc1, OC-STAMP, and c-Fos. These inhibitory effects were associated with suppressing NF-κB transcriptional activation and subsequent reduced nuclear translocation. The decrease in NF-κB activity resulted from reduced activation of its upstream kinases, including I-κBα and IKKα. Moreover, PP902 significantly inhibited RANKL-induced p38MAPK and ERK1/2 activities. Nevertheless, PP902 treatment prevents RANKL-induced intracellular reactive oxygen species generation via increased HO-1 activity. The combined antioxidant and anti-inflammatory effects of PP902 resulted in significant suppression of osteoclastogenesis, suggesting its potential as an adjuvant therapy for osteoclast-related diseases.

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.

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.

Bioinformatically predicted emulsifying peptides and potato protein hydrolysate improves the oxidative stability of microencapsulated fish oil

The aim of this study was to investigate the potential of potato proteins and peptides as emulsifiers in the microencapsulation of fish oil by spray-drying. Microcapsules were produced using a potato protein extract, and fractions enriched in patatin and protease inhibitors. Furthermore, bioinformatically predicted emulsifier peptides from abundant potato proteins and a hydrolysate, obtained through targeted proteolysis of the extract, were investigated. During 28 days of storage at 25 °C, peptides and the hydrolysate exhibited better emulsifying properties and higher encapsulation efficiencies compared to native proteins and sodium caseinate. Significant differences (p < 0.05) were observed in the peroxide value (PV) and secondary volatile oxidation products between the microcapsules produced with peptides and native proteins. Microcapsules produced with peptides and hydrolysate showed the highest oxidative stability, not exceeding a PV of 10 meq/kg oil, and with concentrations of volatiles below the odor threshold in oil for five of the six studied compounds. These results show the emulsifying potential of potato peptides and hydrolysate for use in microencapsulation of hydrophobic bioactive ingredients such as fish oil.

Physical and Oxidative Stability of Emulsions Stabilized with Fractionated Potato Protein Hydrolysates Obtained from Starch Production Side Stream.

This work studies the emulsifying and antioxidant properties of potato protein hydrolysates (PPHs) fractions obtained through enzymatic hydrolysis of potato protein using trypsin followed by ultrafiltration. Unfractionated (PPH1) and fractionated (PPH2 as >10 kDa, PPH3 as 10-5 kDa, PPH4 as 5-0.8 kDa, and PPH5 as <0.8 kDa) protein hydrolysates were evaluated. Pendant drop tensiometry and dilatational rheology were applied for determining the ability of PPHs to reduce interfacial tension and affect the viscoelasticity of the interfacial films at the oil-water interface. Peptides >10 kDa showed the highest ability to decrease oil-water interfacial tension. All PPH fractions predominantly provided elastic, weak, and easily stretchable interfaces. PPH2 provided a more rigid interfacial layer than the other hydrolysates. Radical scavenging and metal chelating activities of PPHs were also tested and the highest activities were provided by the unfractionated hydrolysate and the fractions with peptides >5 kDa. Furthermore, the ability of PPHs to form physically and oxidatively stable 5% fish oil-in-water emulsions (pH 7) was investigated during 8-day storage at 20 °C. Our results generally show that the fractions with peptides >5 kDa provided the highest physicochemical stability, followed by the fraction with peptides between 5 and 0.8 kDa. Lastly, promising sensory results with mostly mild attributes were obtained even at protein concentration levels that are higher than needed to obtain functional properties. The more prominent attributes (e.g., bitterness and astringency) were within an acceptable range for PPH3 and PPH4.

Mechanical Properties, Microstructure, and In Vitro Digestion of Transglutaminase-Crosslinked Whey Protein and Potato Protein Hydrolysate Composite Gels.

The production of animal protein usually leads to higher carbon emissions than that of plant protein. To reduce carbon emissions, the partial replacement of animal protein with plant protein has attracted extensive attention; however, little is known about using plant protein hydrolysates as a substitute. The potential application of 2 h-alcalase hydrolyzed potato protein hydrolysate (PPH) to displace whey protein isolate (WPI) during gel formation was demonstrated in this study. The effect of the ratios (8/5, 9/4, 10/3, 11/2, 12/1, and 13/0) of WPI to PPH on the mechanical properties, microstructure, and digestibility of composite WPI/PPH gels was investigated. Increasing the WPI ratio could improve the storage modulus (G') and loss modulus (G″) of composite gels. The springiness of gels with the WPH/PPH ratio of 10/3 and 8/5 was 0.82 and 0.36 times higher than that of the control (WPH/PPH ratio of 13/0) (p < 0.05). In contrast, the hardness of the control samples was 1.82 and 2.38 times higher than that of gels with the WPH/PPH ratio of 10/3 and 8/5 (p < 0.05). According to the International Organization for Standardization of Dysphagia Diet (IDDSI) testing, the composite gels belonged to food level 4 in the IDDSI framework. This suggested that composite gels could be acceptable to people with swallowing difficulties. Confocal laser scanning microscopy and scanning electron microscopy images illustrated that composite gels with a higher ratio of PPH displayed thicker gel skeletons and porous networks in the matrix. The water-holding capacity and swelling ratio of gels with the WPH/PPH ratio of 8/5 decreased by 12.4% and 40.8% when compared with the control (p < 0.05). Analysis of the swelling rate with the power law model indicated that water diffusion in composite gels belonged to non-Fickian transport. The results of amino acid release suggested that PPH improved the digestion of composite gels during the intestinal stage. The free amino group content of gels with the WPH/PPH ratio of 8/5 increased by 29.5% compared with the control (p < 0.05). Our results suggested that replacing WPI with PPH at the ratio of 8/5 could be the optimal selection for composite gels. The findings indicated that PPH could be used as a substitute for whey protein to develop new products for different consumers. Composite gels could deliver nutrients such as vitamins and minerals to develop snack foods for elders and children.

The foaming properties of sweet potato protein hydrolysates produced by Alcalase and Ficin.

The processing of sweet potatoes generates a waste by-product rich in sweet potato protein (SPP). In this study, the effects of the concentrations of Alcalase and Ficin, hydrolysis time and pH value on the foaming properties of SPP hydrolysates (SPPHs) determined via gas sparging method were investigated. The results showed that SPPH prepared by Alcalase exhibited a significantly higher foaming expansion (the highest of 576%) than that of the SPP (462%) but displayed a weaker liquid volume stability compared with SPPH hydrolyzed by Ficin. The molecular weight of SPPH prepared by Alcalase was distributed in 10-30 kDa. A good microbiological quality of the SPPH prepared by Alcalase in pH 13 has been confirmed, and it is suitable for food application with respect to its microbiological safety profile. SPPH (pH 13) could be further safely applied in food, especially as a food additive at low concentrations to create a better organic plant-based foaming agent for the food industry. © 2023 Society of Chemical Industry.

The alleviative effect of sweet potato protein hydrolysates on the quality deterioration of frozen dough bread in comparison to trehalose

The effects of different sweet potato protein hydrolysates (SPPH) concentrations (1, 2, 3, g/100 g) on the frozen dough bread in comparison to trehalose (3 g/100 g) were evaluated. The results showed that the addition of SPPH at all examined levels can retard the quality deterioration of frozen dough and a greater amount of SPPH showed better effect. During the frozen storage, the addition of 3 g SPPH showed an increase in yeast viability from 43.01% to 79.03%, and a decrease in freezable water content, tan δ and free sulfhydryl groups from 57. 21%, 0.74 and 5.74 μmol/g to 47.72%, 0.69 and 3.96 μmol/g, respectively. After frozen storage for 56 days, compared with the control, the addition of SPPH at 3 g significantly increased the specific volume of bread from 3.15 mL/g to 3.97 mL/g, and the porosity and mean area of pore increased from 23.18%, 0.26–32.55%, 0.43, respectively, authenticated by the observations of SEM, binary and representative images. Furthermore, the hardness significantly decreased from 1224.90 g to 839.93 g. These findings suggested that SPPH can be potently employed as a natural food-derived cryoprotectant agent for improving the quality and nutrition of frozen dough.

Targeted hydrolysis of native potato protein: A novel workflow for obtaining hydrolysates with improved interfacial properties

Peptides and protein hydrolysates are promising alternatives to substitute chemical additives as functional food ingredients. In this study, we present a novel workflow for producing a potato protein hydrolysate with improved emulsifying and foaming properties using quantitative proteomics and bioinformatic prediction to facilitate targeted hydrolysis design. Based on previous studies, we selected 15 potent emulsifier peptides derived from abundant potato proteins as targets. Through in silico analysis, we determined that from a range of industrial proteases (Neutrase (Neut), Alcalase (Alc), Flavourzyme (Flav) and Trypsin (Tryp)), Tryp was found more likely to release peptides resembling the targets. After applying all proteases individually, hydrolysates were assayed for in vitro emulsifying and foaming properties. No direct correlation between degree of hydrolysis and interfacial properties was found. Tryp (E/S = 3%) produced a hydrolysate (DH = 5.4%) with high aqueous solubility and the highest (P < 0.05) emulsifying and foaming abilities, validating the hypothesis. Using LC-MS/MS, we identified >10,000 peptides in each hydrolysate. Peptide mapping revealed that random overlapping with known peptide emulsifiers is not sufficient to quantitatively describe hydrolysate functionality. However, validated release of targeted peptides by 3% Tryp appears to increase surface activity of the hydrolysate. Our data also suggest that terminal hydrophobic anchor domains may be important for high interfacial partitioning and activity. While modest yields and residual unhydrolyzed protein indicate room for process improvement, this work shows that bioinformatics-guided and data-driven targeted hydrolysis is a promising, interdisciplinary approach to facilitate process design for production of functional hydrolysates from alternative protein sources.

Production, identification and characterization of antioxidant peptides from potato protein by energy-divergent and gathered ultrasound assisted enzymatic hydrolysis

Effects of energy divergent ultrasound (EDU, 30, 40 and 50 W/L) and energy gathered ultrasound (EGU)-assisted enzymatic hydrolysis on production, identification and characterization of antioxidant peptides from potato protein hydrolysates (PPH) were investigated. EDU and EGU significantly increased degree of hydrolysis and recovery of PPH compared with conventional (C) enzymatic hydrolysis. PPH by EGU40 showed the highest Fe2+-chelating activity (55.33 µg EDTA/mL), ·OH scavenging activity (230.05 µg Vc/mL) and oxygen radical absorbance capacity (82.24 µg TE/mL). Peptides with molecular weight <1 and 1–2 kDa of PPH by EGU40 displayed higher antioxidant activities than those by C and EDU40, which might be contributed to their more hydrophobic, polar charged and antioxidant amino acids at terminals and/or inside the sequences identified by LC-MS/MS. Additionally, structure–activity relationship was revealed by peptide conformation and position of some specific amino acids. Therefore, EGU has great potential in production of functional peptides with enhanced antioxidant activity.

Dipeptide IF and Exercise Training Attenuate Hypertension in SHR Rats by Inhibiting Fibrosis and Hypertrophy and Activating AMPKα1, SIRT1, and PGC1α.

Bioactive peptides are physiologically active peptides produced from proteins by gastrointestinal digestion, fermentation, or hydrolysis by proteolytic enzymes. Bioactive peptides are resorbed in their whole form and have a preventive effect against various disease conditions, including hypertension, dyslipidemia, inflammation, and oxidative stress. In recent years, there has been a growing body of evidence showing that physiologically active peptides may have a function in sports nutrition. The present study aimed to evaluate the synergistic effect of dipeptide (IF) from alcalase potato protein hydrolysates and exercise training in hypertensive (SHR) rats. Animals were divided into five groups. Bioactive peptide IF and swimming exercise training normalized the blood pressure and decreased the heart weight. Cardiac, hepatic, and renal functional markers also normalized in SHR rats. The combined administration of IF peptide and exercise offer better protection in SHR rats by downregulating proteins associated with myocardial fibrosis, hypertrophy, and inflammation. Remarkably, peptide treatment alongside exercise activates the PI3K/AKT cell survival pathway in the myocardial tissue of SHR animals. Further, the mitochondrial biogenesis pathway (AMPKα1, SIRT1, and PGC1α) was synergistically activated by the combinatorial treatment of IF and exercise. Exercise training along with IF administration could be a possible approach to alleviating hypertension.

Bioactive Peptides and Exercise Modulate the AMPK/SIRT1/PGC-1α/FOXO3 Pathway as a Therapeutic Approach for Hypertensive Rats.

Peptides are fragments of fundamental protein sequences that may have health benefits in addition to basic dietary benefits. Recently, we have reported on the pharmacological benefits of alcalase potato protein hydrolysate (APPH) and bioactive peptides isolated from APPH. The aim was to evaluate the synergistic effect of exercise along with DIKTNKPVIF (DF) peptides in ameliorating hypertension in spontaneously hypertensive rat (SHR) rats. We examined ECG parameters, lipid profiles, cardiac markers, and histology, and quantified the proteins associated with fibrosis, hypertrophy, apoptosis, mitochondrial biogenesis, and longevity pathways. DF peptide administration, along with exercise, reduced the blood pressure and cardiac marker levels in serum. Furthermore, it also suppressed the expression of fibrosis markers COL1A1, CTGF, and uPA and downregulated cardiac-hypertrophy-associated markers such as calcineurin, NFATC3, GATA4, pGATA4 and BNP. Exercise synergistically increases the expression of IFG1, PI3K, and AKT cell-survival pathway proteins, along with DF administration. Moreover, AMPK/SIRT1/PGC-1α/FOXO3 pathway protein expression was increased with the combinatorial administration of DF and exercise. Our data suggest that exercise, along with DF peptides, act synergistically in alleviating hypertension by activating the mitochondrial biogenesis pathway.

In vitro antioxidant activity and antidiabetic effect of fractionated potato protein hydrolysate via ultrafiltration and adsorption chromatography

Potato processing effluents represent a potential source of valuable proteins for the production of bioactive peptides. In this study, potato protein was hydrolyzed with Alcalase and fractionated using ultrafiltration (10, 2 kDa molecular weight cut off) and adsorption chromatography (adsorbent resin XAD-16 column). Potato protein hydrolysates (PHM and PHC), membrane fractions PHR1 (>10 kDa), PHR2 (2–10 kDa) and PHR3 (<2 kDa) and column fractions PF1 (hydrophilic) and PF2 (hydrophobic) were investigated for antioxidant activity, α-glucosidase and α-amylase inhibition. In addition, α-amylase kinetic inhibition, fluorescence quenching and surface hydrophobicity were evaluated. PF2 fraction showed the best antioxidant activity with the highest ABTS•+ scavenging activity, Fe2+ chelating and DPPH• scavenging activity. PHR1 was the most active against α-amylase whereas α-glucosidase activity was weak for all samples. Fluorescence quenching results of α-amylase showed higher red shift after interaction with PHR1 than PF2. Higher quenching constant for PHR1 demonstrated higher affinity and interaction between this fraction and the enzyme than PF2. Enzyme kinetic studies revealed that PHR1 and PF2 fractions reduced α-amylase activity through uncompetitive and mixed inhibition, respectively. These results demonstrate higher antioxidant activity for hydrophobic fraction and higher α-amylase inhibitory activity for high molecular weight fraction of the potato hydrolysates.

Effects of ultrasound‐assisted enzymatic hydrolysis and monosaccharides on structural, antioxidant and flavour characteristics of Maillard reaction products from sweet potato protein hydrolysates

SummaryEffects of ultrasound (US)‐assisted enzymatic hydrolysis and different monosaccharides (arabinose; xylose, XY; galactose and glucose) on peptide structure, antioxidant activities and flavour characteristics of Maillard reaction products (MRP) from sweet potato protein hydrolysates were investigated. US markedly enhanced the MR progress, and USXY showed the lowest pH value of 5.04, the highest browning intensity and fluorescence intensity (P &lt; 0.05). FTIR results revealed significant peptide structure changes in USXY, USAR and USGA compared to other samples. USXY exhibited the highest Oxygen radical absorbance capacity (ORAC) value of 109.15 µg TE/mL, followed by USGA and USAR (94.07 and 93.41 µg TE/mL), respectively (P &lt; 0.05). USXY and USAR showed different aroma features as compared to other MRP (P &lt; 0.05). In addition, US enhanced umami, sweetness and sourness attributes and reduced bitterness of all MRP. USXY exhibited the highest umami intensity score (7.4), followed by USGA (7.3) and USAR (7.2), respectively. Partial least square regression analysis showed that the stronger umami taste was strongly correlated to aldehydes, thiophenes, MW 1000–3000 and 500–1000 Da peptides. Thus, US‐assisted enzymatic hydrolysis and MR with xylose (XY) could be a promising way to produce natural flavouring with improved antioxidant activity.

Structural, antioxidant, aroma, and sensory characteristics of Maillard reaction products from sweet potato protein hydrolysates as influenced by different ultrasound-assisted enzymatic treatments

Effects of energy-divergent ultrasound (EDU), energy-gathered ultrasound (EGU), and energy-gathered ultrasound-microwave (EGUM) on structure, antioxidant activities, aroma, and sensory attributes of Maillard reaction products (MRPs) from sweet potato protein hydrolysates (SPPH) were investigated. EGU and EGUM markedly enhanced the Maillard reaction (MR) progress. FTIR results revealed significant peptide structure changes in MRPs as compared to their SPPHs counterparts. EGU-MRPs exhibited the highest percentages in lower MW fractions of 200–3,000 Da, and presented a significantly enhanced ORAC value of 92.10 µg TE/mL (p < 0.05). Besides, EGU-MRPs and EGUM-MRPs showed higher content and quality of aroma compounds than other MRPs, and presented increased umami, sweetness, and sourness attributes, but decreased bitterness (p < 0.05). Their stronger umami taste was highly correlated to 1-naphthalenol, dodecanoic acid, <200, 200–500, 500–1,000 and 1,000–3,000 Da. Thus, EGU and EGUM assisted enzymatic hydrolysis coupled with MR might be promising ways to produce natural flavoring with improved antioxidant activities.

Bioactive dipeptide from potato protein hydrolysate combined with swimming exercise prevents high fat diet induced hepatocyte apoptosis by activating PI3K/Akt in SAMP8 mouse.

Obesity in aged population have surges the occurrence of various metabolic disorders including Nonalcoholic fatty liver disease (NAFLD). Apoptosis in the liver is one of the causative factors for NAFLD-induced liver damage. Plants derived bioactive peptides have been shown as an alternative treatment approach for the treating NAFLD due to its less toxicity. Moderate exercise has been reported to improve cellular physiological function prevent age associated metabolic disorders. In the present study, we evaluate the effects of bioactive dipeptide (IF) derived from alcalase potato-protein hydrolysates and swimming exercise in preventing High Fat Diet (HFD)-induced liver damage in senescence accelerated mouse-prone 8 (SAMP8) mice model. Mouse were fed with HFD for 6weeks followed by oral IF administration or swimming exercise and both for 8weeks. HFD induces significant structural changes in liver of HFD fed SAMP8 mouse. Both IF administration and exercise prevent the structural abnormalities induced by HFD, however, combined IF treatment and exercise offer better protection. Combined IF treatment and exercise activate PI3K/Akt cell survival protein and effectively inhibit Fas-FADD-induced apoptosis in HFD fed aged mouse. Oral supplementation of bioactive peptide IF combined with moderate swimming exercise effectively alleviate HFD-induced hepatic injury in aged mice.

Improvement of ultrasound microwave-assisted enzymatic production and high hydrostatic pressure on emulsifying, rheological and interfacial characteristics of sweet potato protein hydrolysates

Herein, we investigated effects of ultrasound microwave (UM)-assisted enzymatic hydrolysis and high hydrostatic pressure (HHP, 300, 400 and 500 MPa) on emulsifying, rheological and interfacial characteristics of sweet potato protein hydrolysates (SPPH). UM significantly improved emulsifying properties of SPPH. Emulsion stabilized with SPPH by UM at 400 MPa was the most physically stable with ESI of 43.16% compared with other emulsions, which showed lower particle size (239.25 nm) but higher zeta potential (26.75 mV). HHP increased adsorption and antioxidant activity of SPPH at interfacial layer. Emulsion stabilized with UM-SPPH400MPa presented the highest adsorbed peptides at interface (23.79%) with a high ORAC value of 100.49 μg TE mL−1, from which diverse peptides with potential antioxidant activities were obtained by LC-MS/MS. Additionally, changes in peptide conformation and position of some specific amino acids were revealed by structure-activity relationship analysis. Therefore, ultrasound-microwave and HHP have great potential in peptides production with enhanced functionality.

Role of potato protein hydrolysate and exercise in preventing high-fat diet-induced hepatocyte apoptosis in senescence-accelerated mouse.

Nonalcoholic fatty liver disease (NAFLD) is considered to be a serious clinical complication, which could cause significant liver dysfunction including fibrosis, cirrhosis, and cancer. Obesity could lead to NAFLD and contributes to liver disorder and related complicated liver diseases. Effect of exercise combined with alcalase treatment derived potato protein hydrolysate (APPH) on high-fat diet (HFD)-induced hepatic injury was investigated in senescence accelerated mouse-prone 8 (SAMP8) mice in the present study. Mice were divided into six groups (n=6): Group I-Control, Group II-HFD, Group III-Exercise, Group IV-HFD+APPH, Group V-HFD+Exercise, and Group VI-HFD+Exercise+APPH. Combined APPH treatment and exercise offer better cytoprotection in HFD-induced histological changes than APPH treatment and exercise alone. Further, APPH and exercise activate the cell survival proteins PI3K/Akt and prevent FasL/FADD-mediated apoptosis in HFD fed SAMP8 mouse. APPH with swimming exercise effectively modulate HFD-induced liver damage and apoptosis in aged mice through activation of PI3K/Akt protein. PRACTICAL APPLICATIONS: Exercise training is proven to reduce the health problems associated with aging and obesity, however, intensity and duration of the exercise differs between individuals. We used integrated pharmacological and nonpharmacological approach as a therapeutic strategy for preventing HFD-induced hepatic injury in aged subjects.

Prediction and Identification of Antioxidant Peptides in Potato Protein Hydrolysate

Principal component analysis (PCA) was used to cluster the possible amino acid compositions of antioxidant peptides in potato protein hydrolysate (PPH). The antioxidant peptides exhibiting high ABTS+• scavenging capacity were isolated with the procedure of ultrafiltration, gel filtration, and preparative RP-HPLC and identified by UPLC-MS/MS. Phe, Tyr, and His were shown to group together with ABTS+• scavenging capacity in component matrix plot. Three prominent peptides, namely, Phe-Tyr, Tyr-Phe-Glu, and Pro-Pro-His-Tyr-Phe, which matched the sequence of patatin and were made up of Phe and Tyr, were identified. The peptide Tyr-Phe-Glu demonstrated antioxidant activity against Caco-2 cell oxidation induced by H2O2. The results suggested that multivariate analysis could be used to predict the amino acid compositions of antioxidant peptides.