RESUMO
BACKGROUND: Sweet potato (Ipomoea batatas L.) is the sixth most important food crop in the world, and China is the largest producer. Large amounts of sweet potato residues are generated during starch extraction, leading to environmental pollution and resource waste. However, these residues can be used as a viable source for pectin extraction. As a natural biopolymer with high molecular weight and complex structure, the usefulness of pectin has been limited, and it needs to be modified in order to improve its physicochemical properties, thus expanding its applications in the food industry. Therefore, the reported study was conducted to modify sweet potato pectin (SPP) using high hydrostatic pressure (HHP) and/or pectinase treatment, and to determine the effects of such treatment on structural, physicochemical and emulsifying properties. RESULTS: The results demonstrated that the molecular weight of SPP decreased following HHP and pectinase treatment, which was evidenced using scanning electron microscopy and atomic force microscopy. The degree of esterification was also decreased, confirmed by decreased intensity of the peak at 1739 cm-1 in the Fourier transform infrared spectrum and decreased peaks at 3.6 and 3.8 ppm in the 1 H NMR spectrum. Moreover, the content of monosaccharides and uronic acids increased and emulsifying properties improved after HHP and pectinase treatment. CONCLUSIONS: HHP-assisted pectinase treatment could be used as novel technique for the modification of pectin to give better emulsifying properties with great potential for application in the food industry. © 2020 Society of Chemical Industry.
Assuntos
Ipomoea batatas/química , Pectinas/química , Poligalacturonase/química , China , Emulsões/química , Manipulação de Alimentos , Pressão Hidrostática , Peso Molecular , Amido/química , ViscosidadeRESUMO
Effects of ultrasonication, boiling, steaming, microwaving and autoclaving pretreatments on the production of sweet potato protein hydrolysates (SPPH) by single and combined Alcalase (ALC) and Protease (PRO) were investigated, as well as antioxidant activities of SPPH subjected to in vitro gastrointestinal digestion (GID). All pretreatments significantly increased the degree of hydrolysis (DH) and antioxidant activities of SPPH by ALC, PRO and ALC + PRO in the order of autoclaving > steaming, microwaving, boiling > ultrasonication (P < 0.05). GID significantly enhanced antioxidant activities and increased MW <3 kDa peptide fraction contents of all SPPH. Diverse peptides were identified as sporamin A, A precursor and sporamin B before and after GID from LC-QTOF-MS/MS analysis. Peptides with higher antioxidant amino acids of Trp, Tyr, Met, Cys, His and Phe were found after GID. There is a great potential application of SPPH as a novel food ingredient as a natural antioxidant.
Assuntos
Antioxidantes/metabolismo , Ipomoea batatas/metabolismo , Peptídeos/metabolismo , Proteínas de Plantas/metabolismo , Hidrolisados de Proteína/metabolismo , Precursores de Proteínas/metabolismo , Aminoácidos/metabolismo , Digestão , Hidrólise , Peptídeo Hidrolases/metabolismo , Subtilisinas/metabolismoRESUMO
Antiproliferative effect of Amaranthus mantegazzianus proteins and peptides released after simulated gastrointestinal digestion (DH% 37.8 ± 3.8) was investigated on human colon cancer cell line HT-29. Inhibition of proliferation of HT-29 cells was exhibited after a 24 h treatment with different concentrations of amaranth protein isolate (API) and the peptides released after digestion (DGS), presenting IC50 values of 1.35 ± 0.12 and 0.30 ± 0.07 mg soluble protein/mL, respectively. Lactate dehydrogenase assay indicated that both samples caused the loss of membrane integrity and cell lysis over HT-29 cells, and DAPI fluorescence microscopies evidenced typical apoptotic features. Moreover, Annexin V-FITC flow cytometry showed a significant increase of early apoptotic and late apoptotic/necrotic HT-29 cells compared to untreated ones, and caspase-3 assay confirmed the apoptosis induction with a 43.0 ± 10.3 and 65.8 ± 12.7% increase of caspase-3 activity produced by a 2 mg/mL treatment of API and DGS, respectively. In conclusion, amaranth peptides successfully released after simulated gastrointestinal digestion would exert a potential antiproliferative activity over HT-29 tumor cells. This effect was linked to the induction of cell necrosis and apoptosis, supporting the idea of using amaranth proteins as a potential food alternative ingredient for functional foods.
Assuntos
Amaranthus/química , Proliferação de Células/efeitos dos fármacos , Alimento Funcional , Peptídeos/farmacologia , Proteínas de Plantas/farmacologia , Apoptose/efeitos dos fármacos , Digestão , Células HT29 , HumanosRESUMO
Response surface methodology was used to analyze effects of the amounts of pregelatinized potato flour (PGPF), hydroxypropylmethylcellulose (HPMC), egg white protein (EWP), and water on the dough fermentation and physical properties of gluten-free (GF) steamed bread based on potato flour. The results showed that PGPF, HPMC, EWP, and water at the appropriate amounts improved the maximum dough height (H m), specific volume (SV) and hardness, as well as H m correlated with SV (R 2 = 0.6993) and hardness (R 2 = 0.7273). Moreover, the optimal formulation contained 4.84 g/100 g PGPF, 1.68 g/100 g HPMC, 5.87 g/100 g EWP, and 69.69 g/100 g water, potato flour basis. Furthermore, the dietary fiber, total polyphenol content, antioxidant activity, and estimated glycemic index of the steamed GF bread were, respectively, 3.17-, 1.56-, 1.44-, and 0.75-fold of those of steamed wheat bread. The optimized steamed GF bread was found to be acceptable according to the results of sensory analysis. Information collected within this study may provide further insight for optimizing the formulation of steamed GF bread based on potato flour.
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BACKGROUND: Pectin and especially modified citrus pectin possesses anticancer activity. Hence, the current study investigated anticancer activity of ultrasonic-modified sweet potato pectin (SPP) on HT-29 cells to assess its potential as a cancer therapeutic agent. METHOD: The effect of ultrasonic treatment on SPP molecular weight, galacturonic acid content, degree of methoxylation, and neutral sugar was investigated. Moreover, the effect of sonicated variant on human HT-29 cell proliferation was assessed by MTT assay, cell cytotoxicity, and apoptosis by Annexin V/PI flow cytometer and caspase-3 activity was studied. RESULTS AND DISCUSSION: Sonication led up to seven-fold decrease in molecular weight. The degree of methoxylation (DM) decreased more than two-fold. Moreover, the galacturonic acid (GalA) content increased up to 92%, arabinose and galactose content increased. The SSPP inhibited cell proliferation with the IC50 values 0.5 mg/ml and 0.75 mg/ml for 400 W and 200 W SSPP, respectively. Moreover, 14.41 ± 1.64% cell cytotoxicity was elicited by 400 W SSPP and 6.83 ± 0.80% by 200 W SSPP. Both SSPPs induced apoptosis with 400 W SSPP eliciting 19.42% and 42.21% apoptosis at 0.1 and 0.5 mg/ml, while 200 W SSPP induced 13.79% and 39.50% apoptosis at 0.1 and 0.5 mg/ml, respectively. SSPP activity increased with both increased concentration and sonication intensity.
Assuntos
Antineoplásicos Fitogênicos/farmacologia , Ipomoea batatas/química , Pectinas/química , Pectinas/farmacologia , Ultrassom/métodos , Apoptose/efeitos dos fármacos , Caspase 3/metabolismo , Proliferação de Células/efeitos dos fármacos , Células HT29 , Ácidos Hexurônicos/análise , Humanos , L-Lactato Desidrogenase/metabolismo , Peso MolecularRESUMO
We investigated the nutritional quality of steamed and baked breads containing 35% potato flour from four potato cultivars. Compared with traditional wheat varieties, potato-wheat steamed and baked breads contained higher dietary fiber (1.87-fold), K (2.68-fold), vitamin C (28.56-fold), and total polyphenol (1.90-fold) contents and greater antioxidant activity (1.23-fold). Moreover, the estimated glycemic index of potato-wheat breads ranged from 61.20 (Hongmei-wheat baked bread) to 67.36 (Atlantic-wheat steamed bread), which was lower than that of wheat steamed bread (70.22) and baked bread (70.62). In terms of nutritional value, Hongmei was the optimum cultivar, followed by Blue Congo, Shepody, and Atlantic. For the same cultivar, the nutritional value of steamed bread was higher than that of baked bread. In conclusion, potato flour is a potential wheat flour supplement that improves the nutritional and functional properties of breads.
Assuntos
Pão/análise , Farinha , Manipulação de Alimentos , Valor Nutritivo , Solanum tuberosum , Triticum , Aminoácidos/análise , Antioxidantes/análise , Fibras na Dieta/análise , Digestão , Índice Glicêmico , Modelos Lineares , Polifenóis/análise , Oligoelementos/análise , Vitaminas/análiseRESUMO
Patatin represents a group of homologous primary storage proteins (with molecular weights ranging from 40 kDa to 45 kDa) found in Solanum tuberosum L. This group comprises 40% of the total soluble proteins in potato tubers. Here, patatin (40 kDa) was extracted from potato fruit juice using ammonium sulfate precipitation (ASP) and exposed to high hydrostatic pressure (HHP) treatment (250, 350, 450, and 550 MPa). We investigated the effect of HHP treatment on the structure, composition, heat profile, and antioxidant potential, observing prominent changes in HHP-induced patatin secondary structure as compared with native patatin (NP). Additionally, significant (p < 0.05) increases in ß-sheet content along with decreases in α-helix content were observed following HHP treatment. Thermal changes observed by differential scanning calorimetry (DSC) also showed a similar trend following HHP treatment; however, the enthalpy of patatin was also negatively affected by pressurization, and free sulfhydryl content and surface hydrophobicity significantly increased with pressurization up to 450 MPa, although both interactions progressively decreased at 550 MPa. The observed physicochemical changes suggested conformational modifications in patatin induced by HHP treatment. Moreover, our results indicated marked enhancement of antioxidant potential, as well as iron chelation activities, in HHP-treated patatin as compared with NP. These results suggested that HHP treatment offers an effective and green process for inducing structural modifications and improving patatin functionality.
Assuntos
Antioxidantes/química , Antioxidantes/farmacologia , Hidrolases de Éster Carboxílico/química , Hidrolases de Éster Carboxílico/farmacologia , Pressão Hidrostática , Estrutura Molecular , Proteínas de Plantas/química , Proteínas de Plantas/farmacologia , Varredura Diferencial de Calorimetria , Hidrolases de Éster Carboxílico/isolamento & purificação , Sequestradores de Radicais Livres/química , Sequestradores de Radicais Livres/farmacologia , Interações Hidrofóbicas e Hidrofílicas , Quelantes de Ferro/química , Quelantes de Ferro/farmacologia , Peso Molecular , Compostos Fitoquímicos , Proteínas de Plantas/isolamento & purificação , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
The aim of study was to investigate the effect of hydroxylpropylmethylcellulose (HPMC), arabic gum (AG), konjac glucomannan (KG) and apple pectin (AP) at 2% (w/w, potato-wheat flour basis) on the potato-wheat dough (the mass ratio was 1:1) rheological, fermentation and bread making properties. The tan δ of potato-wheat dough was significantly increased upon addition of adding HPMC which was close to wheat dough (0.531). Moreover, dough height during fermentation process was significantly improved on addition of hydrocolloids, with the order of HPMC (23.1 mm) > AP (19.3 mm) > AG (18.6 mm) > KG (13.6 mm). Protein bands of potato-wheat dough were pale in the presence of hydrocolloids, suggesting the formation of higher molecular weight aggregates formed between proteins-hydrocolloids or proteins-proteins after fermentation process. Furthermore, HPMC significantly increased specific volume (from 1.45 to 2.22 ml/g), and hydrocolloids restricted the retrogradation of starch in potato-wheat breads.
RESUMO
This study assessed the effects of thermal (40, 60, 80, 100 and 127 °C) and high hydrostatic pressure (HHP, 200, 400 and 600 MPa) treatments on the in vitro digestibility and structural properties of sweet potato protein (SPP). The results showed that the in vitro digestibility of SPP increased significantly with increasing heating temperature and heating time (0-60 min), while HHP treatment had little or no effect. Native SPP denaturation temperature (T d ) and enthalpy change (ΔH) were 89.0 °C and 9.6 J/g, respectively. Thermal and HHP treated SPP had T d of 84.6-88.9 °C and 86.4-87.6 °C, respectively. ΔH of thermal treated SPP was 3.6-6.4 J/g, while that of HHP treated SPP was 5.9-7.8 J/g. The differential scanning calorimetry (DSC) results demonstrated that HHP and thermal treatments both significantly reduced SPP thermodynamic stability. Circular dichroism analyses revealed that native SPP contains α-helixes, ß-sheets and random coils (4.3, 48.0 and 47.7%, respectively). After thermal treatment at 127 °C for 20 min, the content of α-helixes and turns increased significantly (13.2 and 27.6%, respectively), whereas the content of ß-sheets decreased significantly (12.3%). In contrast, HHP treatment increased the content of ß-sheets, but decreased the content of random coils. This study suggested that the SPP structure changes might be the main reason affecting the in vitro digestibility of SPP, and thermal treatment was more effective at changing SPP secondary structures and improving in vitro SPP digestibility than HHP treatment.
Assuntos
Temperatura Alta , Ipomoea batatas/química , Proteínas de Plantas/química , Varredura Diferencial de Calorimetria , Dicroísmo Circular , Digestão , Manipulação de Alimentos , Pressão Hidrostática , Dobramento de Proteína , Estrutura Secundária de ProteínaRESUMO
The spray-drying process to generate microcapsules from Pickering emulsions needs high temperatures, leading to instability of emulsions and degradation of encapsulated thermosensitive compounds (ß-carotene). However, these effects may be attenuated by the introduction of seaweed polyphenols into the emulsion interfacial layers, although the effects underlying this protective mechanism have not been explored. This study evaluates the effects of spray-drying/rehydration on the morphology, encapsulation efficiency, redispersibility, and stability of ß-carotene loaded Pickering emulsions stabilized by chitosan (PESC) and Pickering emulsions stabilized by chitosan/seaweed polyphenols (PESCSP). The encapsulation efficiency of ß-carotene in PESCSP microcapsules (61.13 %) was higher than PESC (53.91 %). Rehydrated PESCSP exhibited more regular droplet size distribution, higher stability, stronger 3D network morphology, and lower redispersibility index (1.5) compared to rehydrated PESC. Analyses of interfacial layers of emulsions revealed that chitosan covalently bound fatty acids at their hydrophobic side. Polyphenols were linked to chitosan at the hydrophilic side of emulsions through hydrogen bonds, providing 3D network between droplets and antioxidant activities to inhibit the degradation of ß-carotene. This study emphasized the role of polyphenols in the interfacial layers of Pickering emulsions for the development of efficient delivery systems and protection of ß-carotene and other thermosensitive bioactive compounds during spray-drying and rehydration.
Assuntos
Quitosana , Emulsões , Polifenóis , Alga Marinha , Secagem por Atomização , beta Caroteno , Quitosana/química , Polifenóis/química , beta Caroteno/química , Alga Marinha/química , Antioxidantes/química , Cápsulas , Tamanho da Partícula , Interações Hidrofóbicas e HidrofílicasRESUMO
In this study, Pickering emulsions stabilized by chitosan (CS), chitosan-Laminaria japonica polyphenols (CP) and chitosan-Ascophyllum nodosum polyphenols (CB) were fabricated. This study also evaluated the stability of CS, CP, and CB under different environmental factors including pH (2-9), NaCl concentrations (0-500 mM), heat treatments (50-100 °C) and storage period (0-8 weeks). The characterization on interfacial layer of emulsion droplets demonstrated that macroalgal polyphenols could combined with the amorphous regions of chitosan particles through hydrogen bond and electrostatic interactions, providing stronger dual wettability with enhanced ability of interfacial layer in stabilizing Pickering emulsions. All three emulsions showed best droplet distribution, highest emulsion stability and specific surface area at pH 6 and 0 mM NaCl concentration as fresh emulsion. Moreover, CS, CP, and CB exhibited the rheological behaviour of pseudoplastic fluids at different pH and NaCl concentration. It should be noted that CP and CB exhibited higher emulsion stability than CS under a variety of environmental stresses. Overall, this research proved that chitosan-macroalgal polyphenol co-stabilized Pickering emulsion had enhanced stability against various environmental stimuli, which could be utilized as potential delivery and protection system for hydrophobic bioactive compounds.
Assuntos
Quitosana , Nanopartículas , Emulsões/química , Quitosana/química , Polifenóis , Cloreto de Sódio/farmacologia , Molhabilidade , Tamanho da Partícula , Nanopartículas/químicaRESUMO
Due to the hydrophilic nature of chitosan, its use as stabilizers in Pickering emulsions requires of hydrophobic modifications that can be achieved by layer-by-layer electrostatic deposition. This study aims to explore and optimize the effects of multiple parameters (chitosan-polyphenol ratio, chitosan concentrations, oil-phase ratios, pH and NaCl concentrations) on the stability of Pickering emulsions stabilized by chitosan and macroalgal polyphenols. The binding mode of chitosan and polyphenols in co-stabilized Pickering emulsions was characterized by Fourier transform infrared spectroscopy (FTIR), confocal scanning laser microscopy (CLSM), scanning electron microscopy (SEM), atomic force microscopy (AFM), and contact angle. The emulsions had the highest physical stability (95.67 %) and specific surface area (2.21 m2/g) at: chitosan-polyphenol ratio 9.5:1 (w:w), chitosan concentration 0.5 % (w/v), oil-phase ratio 5 % (v/v), pH 6, and NaCl concentration 0 mM. FTIR, CLSM, SEM, and AFM evidenced that chitosan and polyphenols were bound by hydrogen bonds and electrostatic interactions at oil-water interfacial layers of emulsions that had a contact angle of 87.8°, indicating that polyphenols combined with chitosan had better ability to stabilize Pickering emulsions compared to chitosan alone. This study broadens the potential applications of naturally extracted macroalgal polyphenols for the development of Pickering emulsions in nutraceutical and functional food industries.
Assuntos
Quitosana , Emulsões/química , Quitosana/química , Polifenóis/química , Eletricidade Estática , Cloreto de Sódio , Tamanho da PartículaRESUMO
BACKGROUND: Chitosan-based particles are one of the most promising Pickering emulsions stabilizers due to its cationic properties, cost-effective, biocompatibility, biodegradability. However, there are currently no comprehensive reviews analyzing the role of chitosan to develop Pickering emulsions, and the bioavailability and multiple uses of these emulsions. SCOPE AND APPROACH: This review firstly summarizes the types, preparation and functional properties of chitosan-based Pickering emulsion stabilizers, followed by in vivo and in vitro bioavailability, main regulations, and future application and trends. KEY FINDINGS AND CONCLUSIONS: Stabilizers used in chitosan-based Pickering emulsions include 6 categories: chitosan self-aggregating particles and 5 types of composites (chitosan-protein, chitosan-polysaccharide, chitosan-fatty acid, chitosan-polyphenol, and chitosan-inorganic). Chitosan-based Pickering emulsions improved the bioavailability of different compounds compared to traditional emulsions. Current applications include hydrogels, microcapsules, food ingredients, bio-based films, cosmeceuticals, porous scaffolds, environmental protection agents, and interfacial catalysis systems. However, due to current limitations, more research and development are needed to be extensively explored to meet consumer demand, industrial manufacturing, and regulatory requirements. Thus, optimization of stabilizers, bioavailability studies, 3D4D printing, fat substitutes, and double emulsions are the main potential development trends or research gaps in the field which would contribute to increase adoption of these promising emulsions at industrial level.
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Quitosana , Emulsões , Disponibilidade Biológica , Tamanho da PartículaRESUMO
This study aimed at realizing high value utilization of purple sweet potato (PSP) peels. Firstly, ultrasonic assisted ethanol method was used to extract anthocyanins from PSP peels, and the individual anthocyanin composition and antioxidant activity were analyzed. Then the technological parameters of preparing cellulose nanocrystals (CNCs) by ultrasonic-assisted maleic acid hydrolysis were optimized, and Zeta-potential, chemical structure, thermal stability and crystallinity of CNCs were analyzed. Results showed the optimal technological parameters were as follows: the ratio between PSP peel residues and 75 wt% maleic acid was 1:10 (g/mL, W/W), and ultrasonic-assisted hydrolysis was carried out at 60â for 1 h, followed by 120â for 2.5 h. The yield and Zeta-potential of CNCs were 8.17 % and -57.7 mV, respectively. The chemical structure and physical properties of CNCs were similar to those of commercial CNCs. In conclusion, ultrasound-assisted maleic acid hydrolysis has great potential to realize the industrialization of CNCs.
Assuntos
Ipomoea batatas , Nanopartículas , Celulose/química , Ipomoea batatas/química , Hidrólise , Antocianinas , Nanopartículas/químicaRESUMO
In this study, the preparation parameters of cellulose nanofibers from potato residues (PCNFs) by ultrasonication combined with high-pressure homogenization were optimized based on yield, zeta-potential and morphology. The optimal parameters were as follows: ultrasonic power of 125 W for 15 min and homogenization pressure of 40 MPa four times. The yield, zeta potential and diameter range of the obtained PCNFs were 19.81 %, -15.60 mV and 20-60 nm, respectively. Fourier transform infrared spectroscopy, X-ray diffraction and nuclear magnetic resonance spectroscopy results showed that part of the crystalline region of cellulose was destroyed, resulting in a decrease in crystallinity index from 53.01 % to 35.44 %. The maximum thermal degradation temperature increased from 283 °C to 337 °C. PCNFs suspensions were non-Newtonian fluids and exhibited rigid colloidal particle properties. In conclusion, this study provided alternative uses for potato residues generated from starch processing and showed great potential for various industrial applications of PCNFs.
Assuntos
Nanofibras , Solanum tuberosum , Celulose/química , Nanofibras/química , Difração de Raios X , Temperatura , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
Due to functional and physicochemical properties, starch in its native state has limited range of applications. Simultaneously, information on effects of different sugars and their interactions with modified starch on gluten-free model dough is also limited. To better overcome these restrictions, the effects of sucrose, trehalose, maltose and xylose on rheology, water mobility and microstructure of gluten-free dough prepared with high hydrostatic pressure (HHP) treated maize (MS), potato (PS) and sweet potato starch (SS) were investigated. MS, PS and SS dough with trehalose exhibited a lower degree of dependence of G' on frequency sweep (z'), higher strength (K) and relative elastic part of maximum creep compliance (Je/Jmax), suggesting stable network structure formation. Total gas production (VT) of MS dough with maltose, PS dough with sucrose and SS dough with trehalose was increased from 588 to 1454 mL, 537 to 1498 mL and 637 to 1455 mL respectively. Higher weakly bound water (T22) was found in the dough with trehalose at 60 min of fermentation, suggesting more hydrogen bonds and stable network. Thus, trehalose might be a potential improver in HHP treated starch-based gluten-free products.
Assuntos
Maltose , Trealose , Xilose , Sacarose , Água/química , Pressão Hidrostática , Amido/química , Reologia , Glutens/química , FarinhaRESUMO
Effects of oxidative browning inhibitors on sweet potato protein (SPP) recovery and quality were studied. Oxidative browning inhibitors successfully decreased sweet potato oxidative browning, but reduced both SPP extractability and recovery. Ultrafiltration/diafiltration processed sweet potato (UDSP) protein (at pH 4, 6 and 7) showed significantly (p<0.05) higher yield, purity, solubility, thermal stability and amino acid constituents than that of isoelectrically precipitated sweet potato (IPSP) protein (at pH 4). The yield of UDSP proteins was more than twice that of IPSP protein. Denaturation temperature (Td), enthalpy change (ΔH) and solubility (at pH 3 and 8) of UDSP proteins were in the ranges 82.89-90.29 °C, 6.34-11.35 (J/g) and 71.4-94.2%, respectively, while that of IPSP protein were 85.27 °C, 2.35 (J/g) 31.2% and 55.5%, respectively. Ratio of SPP essential amino acid to the total amino acid ratio ranged from 0.49 to 0.51. SPP in vitro digestibility and digestibility-corrected amino acid score (PDCAAS) ranged 70-80.7% and 44.79-51.08%, respectively.
Assuntos
Ipomoea batatas/química , Proteínas de Plantas/química , Ultrafiltração/métodos , Aminoácidos/metabolismo , Ácido Ascórbico/química , Ácido Cítrico/química , Ipomoea batatas/metabolismo , Oxirredução , Pigmentação , Proteínas de Plantas/metabolismo , Estabilidade Proteica , Solubilidade , Sulfitos/química , Temperatura , TermodinâmicaRESUMO
The functionalities of hydrocolloids and enzymes in texture, retrogradation enthalpy, water mobility and distribution, and anti-staling effects of potato steamed bread stored for 0, 24, and 48 h at 25 °C were investigated. Four kinds of hydrocolloids, including carrageenan, xanthan gum, arabic gum, sodium alginate, and one kind of enzyme (xylanase) showed little effects on the hardness reduction and springiness retention of potato steamed bread during storage, while the presence of α-amylase and lipase could slow down its staling rate. Potato steamed bread with combination of α-amylase (20 mg/kg) and lipase (40 mg/kg) exhibited the lowest hardness, with a significant reduction of 44.20%, besides improving the specific volume, L*, and overall acceptability in sensory evaluation. The addition of α-amylase and lipase could decrease the retrogradation enthalpy and bound water, and increase the mobility of mobile water. These findings shed efficient methods to retard staling of potato steamed bread.
Assuntos
Pão , Solanum tuberosum , Pão/análise , Coloides , Vapor , ÁguaRESUMO
Sweet potato leaf polyphenols (SPLPs) have shown potential health benefits in the food and pharmaceutical industries. Nowadays, consumption of SPLPs from animal feeds to foodstuff is becoming a trend worldwide. However, the application of SPLPs is limited by their low bioavailability and stability. ß-lactoglobulin (ßlg), a highly regarded whey protein, can interact with SPLPs at the molecular level to form reversible or irreversible nanocomplexes (NCs). Consequently, the functional properties and final quality of SPLPs are directly modified. In this review, the composition and structure of SPLPs and ßlg, as well as methods of molecular complexation and mechanisms of formation of SPLPsßlgNCs, are revisited. The modified functionalities of SPLPsßlgNCs, especially protein conformational structures, antioxidant activity, solubility, thermal stability, emulsifying, and gelling properties including allergenic potential, digestibility, and practical applications are discussed for SPLPs future development.
Assuntos
Ipomoea batatas , Polifenóis , Animais , Antioxidantes , Lactoglobulinas , Extratos Vegetais , Folhas de PlantaRESUMO
This study provides a new idea for improving chlorophyll stability and color quality of green leafy vegetables by Zn2+ synergistic HHP. Zn-chlorophyll was prepared with zinc acetate and chlorophyll under HHP treatment. The effects of different zinc acetate concentrations and pressures on chlorophyll color, antioxidant activity, Zn2+ replacement rate, structure, and thermal stability were analyzed. Results showed with increased zinc acetate concentration and pressure, -a* value, antioxidant activity, and Zn2+ replacement rate of samples gradually increased. However, FTIR indicated the structure did not change. HHP fluorescence online analysis showed fluorescence intensity of samples decreased with zinc acetate concentration and pressure increasing. With zinc acetate 10 mg/100 mL and HHP 500 MPa, the highest -a* value (5.19), antioxidant activity (ABTS, DPPH, and FRAP were 37.03 g ACE/100 g, 25.95 g ACE/100 g, 65.43 g TE/100 g DW, respectively), and Zn2+ replacement rate (42.34%) were obtained. Thermal stability of Zn-chlorophyll obtained by synergistic effect was improved significantly.