Impact of Added Encapsulated Phosphate Level on Lipid Oxidation Inhibition during the Storage of Cooked Ground Meat

The effect of levels (0.1%, 0.2%, 0.3%, 0.4%, 0.5%) of added encapsulated (e) phosphate (sodium tripolyphosphate, STP; sodium hexametaphosphate, HMP; sodium pyrophosphate, SPP) on lipid oxidation inhibition during storage (0, 1, and 7 d) of ground meat (chicken, beef) was evaluated. The use of eSTP and eSPP resulted in lower and higher cooking loss (CL) compared to eHMP, respectively (P < 0.05). Increasing encapsulated phosphate level (PL) enhanced the impact of phosphates on CL in both chicken and beef samples (P < 0.05). Encapsulated STP increased pH, whereas eSPP decreased pH (P < 0.05). pH was not affected by PL. The highest orthophosphate (OP) was obtained with eSTP, followed by eSPP and eHMP (P < 0.05). The level of OP determined in both chicken and beef samples increased (P < 0.05) during storage. Increasing PL caused an increase in OP (P < 0.05). The highest reduction rate in the formation of thiobarbituric acid reactive substances (TBARS) and LPO for both meat species were obtained with eSPP, followed by eSTP and eHMP (P < 0.05). Increasing PL resulted in lower TBARS and LPO (P < 0.05). Findings suggest that encapsulated phosphates can be a strategy to inhibit lipid oxidation for the meat industry and the efficiency of encapsulated phosphates on lipid oxidation inhibition can be enhanced by increasing PL.     

Encapsulated phosphates reduce lipid oxidation in both ground chicken and ground beef during raw and cooked meat storage with some influence on color,pH, and cooking loss

Effects of encapsulated sodium tripolyphosphate (STP), sodium hexametaphosphate (HMP) and sodium pyrophosphate (SPP) on lipid oxidation in uncooked (0, 2, 24 h) and cooked (0, 1, 7 d) ground chicken and beef during storage were determined. Ten phosphate treatments included a control (no phosphate), three unencapsulated (u) at 0.5% and three encapsulated (e) phosphates (0.5%) each at a low (e-low) and high (e-high) coating level. Two heating rates (slow, fast) were investigated. Cooking loss (CL), pH, color, orthophosphate (OP), TBARS and lipid hydroperoxides (LPO) were determined. A fast heating and uSTP resulted in lower CL (p < 0.05). Orthophosphate increased with phosphate incorporation, slow heating and storage (p < 0.05). Encapsulated phosphates and increased coating level reduced OP (p < 0.05). Unencapsulated STP increased CIE a* and pH, whereas uSPP decreased CIE a* and pH (p < 0.05). Encapsulated phosphates and the greater coating level had no effect on the pH in cooked samples. Not increased coating level but encapsulated phosphates decreased lipid oxidation in cooked samples (p < 0.05).     

Reduction in lipid oxidation by incorporation of encapsulated sodium tripolyphosphate in ground turkey

Ground turkey, with 1% NaCl, was incorporated with no sodium tripolyphosphate (control, nSTP), unencapsulated STP (uSTP; 0.3% or 0.5%), encapsulated STP (eSTP; 0.3% or 0.5% active, phosphate basis), or a blend (0.3% uSTP plus 0.2% eSTP). Encapsulate (hydrogenated vegetable oil) was designed to melt at 74 °C. Treatments were stored (4, 24 h at 3 °C) before being cooked to two different endpoints (EPT; 74, 79 °C) followed by post-cooked storage (0, 5, 10 days). An improvement of 77% (0.3% eSTP) and 80% (0.5% eSTP) in the reduction of TBARS was found in comparison to corresponding uSTP. The blend produced a 62% improvement compared to uSTP (0.5%) while maintaining cook yield. CIE a* values were highest at both EPT and post-cooked storage times beyond 0 day for eSTP. Meat manufacturing procedures that entail a delayed thermal processing step will benefit by an improvement in lipid oxidation control through the use of encapsulated phosphates.     

Antioxidative effects of encapsulated sodium tripolyphosphate and encapsulated sodium acid pyrophosphate in ground beef patties cooked immediately after antioxidant incorporation and stored

Ground beef with 1% NaCl was incorporated with 0.5% unencapsulated sodium tripolyphosphate (uSTP), 0.5% encapsulated sodium tripolyphosphate (eSTP), 0.5% unencapsulated sodium acid pyrophosphate (uSAPP), or 0.5% encapsulated sodium acid pyrophosphate (eSAPP) prior to being cooked and stored (0 or 6 d, 3 °C). The pH was higher (P < 0.05) for sodium tripolyphosphate samples (6 d: uSTP 5.98; eSTP 5.89) and lower (P < 0.05) for sodium acid pyrophosphate (6 d: uSAPP 5.31, eSAPP 5.33) samples than control sample (6 d, 5.50). Overall, samples with uSTP had the least cooking loss and lowest TBARS values. TBARS (mg/kg) for the phosphate treatments were lower (P < 0.05; ave. 1.78, 0 d; 3.49, 6 d) than for the control samples (3.07, 0 d; 22.85, 6 d). Therefore, phosphate incorporation into ground beef prior to cooking aids in the reduction of oxidation in the cooked, stored product, although a longer period of time before thermal processing may be necessary for the encapsulated phosphate to have significant benefits.     

Evaluation of Brining Ingredients and Antimicrobials for Effects on Thermal Destruction of Escherichia coli O157:H7 in a Meat Model System

ABSTRACT: Escherichia coli O157:H7 may become internalized during brine injection of meat. This study evaluated the effect of brining ingredients on E. coli O157:H7 in a meat model system after simulated brining, storage, and cooking. Fresh knuckles (5.3 ± 2.4% fat) or beef shoulder (15.3 ± 2.2% fat) were ground individually, mixed with an 8-strain composite of rifampicin-resistant E. coli O157:H7 (7 log CFU/g) and brining solutions. Treatments included no brining, distilled water, sodium chloride (NaCl, 0.5%), sodium tripolyphosphate (STP, 0.25%), sodium pyrophosphate (SPP, 0.25%), NaCl + STP, NaCl + SPP, NaCl + STP + potassium lactate (PL, 2%), NaCl + STP + sodium diacetate (SD, 0.15%), NaCl + STP + PL + SD, NaCl + STP + lactic acid (0.3%), NaCl + STP + acetic acid (0.3%), NaCl + STP + citric acid (0.3%), NaCl + STP + EDTA (20 mM) + nisin (0.0015%) or pediocin (1000 AU/g), NaCl + STP + sodium metasilicate (0.2%), NaCl + STP + cetylpyridinium chloride (CPC; 0.5%), and NaCl + STP + hops beta acids (0.00055%). Samples (30 g) were analyzed for pH, and total microbial and rifampicin-resistant E. coli O157:H7 (inoculum) populations immediately after mixing, storage (24 h at 4 °C), and cooking to 65 °C. Fat and moisture contents and water activity were measured after storage and cooking only; cooking losses also were determined. The effect of beef type on microbial counts, pH, and water activity was negligible. No reductions in microbial counts were obtained by the brining solutions immediately or after storage, except for samples treated with CPC, which reduced (P < 0.05) pathogen counts after storage by approximately 1 log cycle. Cooking reduced pathogen counts by 1.5 to 2.5 logs, while CPC-treated samples had the lowest (P < 0.05) counts compared to any other treatment. These data may be useful in developing/improving brining recipes for control of E. coli O157:H7 in moisture-enhanced beef products.     

磷酸盐和转谷氨酰胺酶对鸡肉肠出品率和硬度的影响

本文主要研究了焦磷酸钠(SPP)、三聚磷酸钠(STP)和六偏磷酸钠(SHMP)对鸡肉肠出品率的影响,并采用L9(34)正交试验设计确定了鸡肉肠中添加复合磷酸盐的最佳配比;通过复合磷酸盐(0.2%、0.3%、0.4%)与转谷氨酰胺酶(0.4%、0.6%、0.8%)析因实验,分析了复合磷酸盐与转谷氨酰胺酶对鸡肉肠质构特性的影响。结果显示,复合磷酸盐的最优配比为STP:SPP:SHMP为4:2:3;复合磷酸盐能显著提高鸡肉肠出品率;转谷氨酰胺酶能显著提高鸡肉肠硬度;二者之间对肉制品出品率及硬度均无显著性交互作用。     

Comparison of Milk Mineral, Sodium Tripolyphosphate, and Vitamin E as Antioxidants in Ground Beef in 80% Oxygen Modified Atmosphere Packaging

The antioxidant effects of milk mineral (MM), sodium tripolyphosphate (STP), and vitamin E (E) were tested in raw ground beef packaged in 80% O₂ modified atmosphere packaging, and held 1, 4, 7, or 14 d at 2 °C. Two levels of each antioxidant (0.75% and 1.5% MM, 0.25% and 0.5% STP, 50 or 100 ppm E) were compared with control samples without added antioxidants. Vitamin E was mixed with mineral oil or ethanol before mixing with meat samples. Thiobarbituric acid (TBA) values were highest (P < 0.05) in controls without antioxidants, and samples with added vitamin E. Lowest TBA values (<0.5) were in samples treated with 0.75% or 1.5% milk mineral. All ground beef samples maintained redness (a* > 10) through 4 d of storage. By day 7, ground beef treatments with added E were brown. After 14 d, ground beef with 0.75% MM was more red (P < 0.05) than other treatments or controls. Thus, 0.75% MM has possible application to prolong red color stability and inhibit lipid oxidation in ground beef packaged in high oxygen atmospheres.     

Antioxidant activity of pomegranate rind powder extract in cooked chicken patties

The radical scavenging activity, reducing power and phenolic composition of pomegranate rind powder extract (RP) were determined and antioxidant properties of RP was evaluated in cooked chicken patties compared with vitamin C (VC) during refrigerated storage. Freshly minced chicken meat were assigned to one of the following six treatments: control (meat without any antioxidant); RP 5, RP 10, RP 15 and RP 20 (5, 10, 15 and 20 mg equivalent RP phenolics 100 g^?1 meat, respectively) and VC 50 (50 mg VC 100 g^?1 meat). The RP exhibited significantly (P < 0.05) higher reducing power and 1,1‐diphenyl‐2‐picrylhydrazyl radical scavenging activity. Incorporation of RP into chicken patties significantly (P < 0.05) reduced the HunterLab L* values compared with control and VC patties. Total phenolic content (as tannic acid equivalent) significantly (P < 0.05) increased from 308 in control to 441 μg g^?1 in RP 20 patties. Addition of RP to chicken patties did not affect any of the sensory attributes. The values of thiobarbituric acid reactive substances were significantly (P < 0.05) reduced from 1.530 in control patties to 0.135 mg malonaldehyde kg^?1 samples in RP patties. Pomegranate rind powder extract treatment (RP 10, RP 15 and RP 20) substantially inhibited (P < 0.05) lipid oxidation in cooked chicken patties to a much greater extent than VC treatment. Therefore, pomegranate rind powder can be utilized as an excellent natural antioxidant source.     

Packaging-specific influence of chitosan on color stability and lipid oxidation in refrigerated ground beef

We examined the influence of chitosan on lipid oxidation and color stability of ground beef stored in different modified atmosphere packaging (MAP) systems. Ground beef patties with chitosan (1%) or without chitosan (control) were packaged either in high-oxygen MAP (HIOX; 80% O₂ + 20% CO₂), carbon monoxide MAP (CO; 0.4% CO + 19.6% CO₂ + 80% N₂), vacuum (VP), or aerobic packaging (PVC) and stored at 1 °C. Chitosan increased (P < 0.05) redness of patties stored in PVC and CO, whereas it had no effect (P > 0.05) in HIOX. Chitosan patties demonstrated lower (P < 0.05) lipid oxidation than controls in all packaging. Control patties in PVC and HIOX exhibited greater (P < 0.05) lipid oxidation than those in VP and CO, whereas chitosan patties in different packaging systems were not different (P > 0.05) from each other. Our findings suggested that antioxidant effects of chitosan on ground beef are packaging-specific.     

Incorporating essential oils of marjoram and rosemary in the formulation of beef patties manufactured with mechanically deboned poultry meat to improve the lipid stability and sensory attributes

The effect of addition of essential oils of marjoram (Origanum marjorana L.) and rosemary (Rosmarinus officinalis L.) at concentration of 200 mg/kg to beef patties formulated with 200 g/kg mechanically deboned poultry meat (MDPM) was studied. The proximate composition, lipid oxidation, sensory characteristics and microbial counts of beef patties manufactured with 200 g/kg MDPM (percentage of lean portion) were assessed during frozen storage at ?18 °C. Beef patties formulated with MDPM (200 g/kg) showed significant (P < 0.05) reduction in protein content and significant (P < 0.05) increase in fat content. Incorporating MDPM in beef patties formulation significantly (P < 0.05) increased the TBARS (Thiobarbituric acid reactive substance) values and significantly (P < 0.05) reduced the flavor and overall acceptability scores. Addition of essential oils of marjoram and rosemary at level of 200 mg/kg significantly (P < 0.05) reduced the TBARS and significantly (P < 0.05) increased the sensory scores of beef patties during frozen storage period. Overall, the study indicated the potential use of natural herbal essential oils to protect against lipid oxidation and improve the sensory attributes of beef patties formulated with MDPM.     

Hexanal as a marker of oxidation flavour in sliced and uncured deli turkey with and without phosphates using rosemary extracts

Ability of commercial rosemary extracts (REs) alone and in combination with sodium tripolyphosphate (P) to inhibit lipid oxidation in uncured deli turkey (UDT) was examined via headspace hexanal and oxidation flavour. Sliced UDT was packaged (75% N₂/25% CO₂) and stored 13 weeks at 4 °C. Addition of P decreased hexanal 2.4-fold (P < 0.05) and increased mean pH of UDT from 5.94 to 6.30 (P < 0.05). Addition of water/lipid-soluble RE did not inhibit hexanal formation in UDT. Addition of water-soluble RE decreased hexanal 2.2-fold (P < 0.05). The combination of P and water-soluble RE decreased hexanal 33-fold (P < 0.05). The combination of P and water/lipid-soluble RE decreased hexanal ninefold (P < 0.05). Oxidation flavour was highest in UDT without added antioxidant> RE> P> RE+P (P < 0.05). Hexanal values were positively correlated with oxidation flavour scores throughout storage (P < 0.05). The combination of P with either RE was particularly effective at inhibiting lipid oxidation in modified atmosphere packaged UDT.     

Antioxidant effects of soy sauce on color stability and lipid oxidation of raw beef patties during cold storage

This study was conducted to evaluate the antioxidant effects of soy sauce on lipid oxidation and color stability of raw beef patties. Raw beef patties were formulated with four solutions such as NaCl (sodium chloride solution), NaCl/SS (1:1 ratio of sodium chloride and soy sauce solution), SS (soy sauce solution), or SS/A (soy sauce solution combined with 0.05% ascorbic acid) in the same salt concentration. Addition of soy sauce resulted in the decreased pH, lightness, and increased yellowness. Treatment SS/A had the lowest percent of metmyoglobin during storage (P < 0.05). A reduction (P < 0.05) in the 2-thiobarbituric acid, peroxide, and conjugated diene concentration as result of soy sauce addition were observed in treatments SS and SS/A at the end of the storage period. There were no differences (P > 0.05) in free fatty acid concentration at the end of storage. The combined addition of soy sauce and ascorbic acid greatly improved (P < 0.05) color stability and retarded lipid oxidation.     

Effects of Oregano Oil Brine Enhancement on Quality Attributes of Beef Longissimus dorsi and Semimembranosus Muscles from Various Age Animals

ABSTRACT: The study reports whether or not oregano oil can reduce lipid oxidation and evaluate palatability variations in beef longissimus dorsi and semimembranosus muscles from various age animals (approximately 18 mo; 18 M, 30 to 60 mo; 30 M, and >60 mo; 60 M). Six muscles of each age group were halved and enhanced with a control brine containing no antioxidants (CN) or a brine containing oregano oil (OR), cut into steaks, and stored in modified atmosphere packaging for 0, 4, 7, and 11 d. Each sampling day, surface color (Minolta L*, a*, b*), lipid oxidation (TBARS), cook yield, sensory analysis, and Warner–Bratzler shear force (WBSF) were measured. OR enhancement decreased TBARS values and slowed the rate of decline in a* values (P < 0.05), but had no effect on WBSF, or sensory tenderness and juiciness scores (P > 0.05) compared to CN steaks. OR steaks had less rancidity detection, more off-flavor, lower overall acceptability in sensory analysis (P < 0.05). This indicated oregano oil can effectively reduce lipid oxidation and extend shelf-life of meat products, but further investigation would be needed to avoid off-flavor and acceptability of product quality. Practical Application: Decreases in meat consumption have led the meat industry to become more innovative in product development. Reducing lipid oxidation is a viable method to reduce rancidity, and improving product acceptability. Our research indicated that although oregano oil did reduce lipid oxidation, the adverse effects of flavor were too great, and thus would not be tolerable in fresh meat products at this concentration. However, there is potential to use oregano oil at lower concentrations and in a variety of processed products which could be beneficial to further the use of natural antioxidants.     

Effect of sodium phytate, sodium pyrophosphate and sodium tripolyphosphate on physico-chemical characteristics of restructured beef

The effects of 0.5% sodium phytate (SPT), sodium pyrophosphate (SPP), and sodium tripolyphosphate (STPP), along with 1% NaCl, on physico-chemical properties of restructured raw and cooked beef were evaluated. In raw beef stored for 1 day at 4 ° C, the SPT, SPP, and STPP increased pH and salt-soluble protein level and decreased %MetMb and thiobarbituric acid reactive substances (TBARS), compared to the control with salt alone (p < 0.05). In cooked beef, SPT, SPP, and STPP increased bind strength, cook yield, moisture level, and pH, and decreased TBARS (p < 0.05). SPP and STPP increased orthophosphate in both raw and cooked beef (p < 0.05), compared to the SPT and control. SPT, SPP, and STPP decreased the Hunter color L and b values and increased a value in raw beef (p < 0.05) but had no effect on the Hunter color values in cooked beef. The binding value of SPP and STPP were similar over time, and the time to reach maximum binding strength was 10s longer than SPT and 25s longer than the control. These results indicate that SPT compares favorably with traditional phosphates for bind strength and cooked yield, but SPT was slightly more effective than other phosphates for reduction of TBARS 1 day after cooking.     

Effects of high hydrostatic pressure on the physicochemical and emulsifying properties of sweet potato protein

The influence of high hydrostatic pressure (HHP) treatment on the physicochemical and emulsifying properties of sweet potato protein (SPP) at various concentrations, e.g. 2%, 4% and 6% (w/v, SPP‐2, SPP‐4 and SPP‐6), was investigated. Significant differences in hydrophobicity, enthalpy of denaturation and solubility were observed (P < 0.05). Emulsifying activity indexes (EAI) of SPP‐2 and SPP‐6 increased at 400 MPa, whereas EAI of all SPP significantly decreased at 600 MPa (P < 0.05). Emulsion stability (ESI) was significantly decreased for SPP‐2 and SPP‐6, while increase in ESI was observed for SPP‐4 above 200 MPa (P < 0.05). SPP‐2 emulsions showed sharp decrease in apparent viscosity with pressure increase, while pseudo plastic flow behaviour was not changed for all of emulsions. Sporamins A and B were well‐adsorbed in pressurised emulsion without displacement. These results suggest that HHP treatment could be used to modify the physicochemical and emulsifying properties of SPP.     

Effect of oregano and thyme essential oils on the microbiological and chemical quality of refrigerated (4 °C) ready‐to‐eat squid rings

The efficacy of oregano and thyme essential oils (OEO and TEO, respectively) in the quality retention of a refrigerated (4 °C) squid (Loligo vulgaris) ring ready‐to‐eat (RTE) product was studied. Essential oils were added at different concentrations to the coating medium during processing. An inhibitory (P < 0.05) effect of OEO on the microbial activity (aerobes, anaerobes, Enterobacteriaceae, psychrotrophs) of the squid rings was observed, with a more pronounced effect as OEO concentration increased. The addition of OEO also led to an inhibitory (P < 0.05) effect on lipid oxidation, as determined by peroxide, thiobarbituric acid‐reactive substance and interaction compound formation; however, no effect (P > 0.05) of the OEO concentrations on lipid oxidation development was detected. The addition of TEO did not lead to an inhibitory effect (P > 0.05) on the microbial activity of the refrigerated RTE squid, although a slight inhibitory (P < 0.05) effect on lipid oxidation was observed in the batches including the higher TEO concentrations.     

Stability of Trans‐Resveratrol Encapsulated in a Protein Matrix Produced Using Spray Drying to UV Light Stress and Simulated Gastro‐Intestinal Digestion

Trans‐resveratrol has demonstrated the potential to provide both therapeutic and preventive activities against chronic diseases such as heart disease and cancer. The incorporation of trans‐resveratrol into food products would allow for broader access of this bioactive compound to a larger population. However, this strategy is limited by instability of trans‐resveratrol under environmental conditions and within the digestive system leading to isomerization of trans‐resveratrol (bioactive form) to cis‐resveratrol (bio‐inactive form). Studies in the stabilization of trans‐resveratrol into protein microparticles are presented. Trans‐resveratrol was encapsulated using whey protein concentrate (WPC) or sodium caseinate (SC), with or without anhydrous milk fat (AMF). Binding of resveratrol and aromatic residues in protein was estimated utilizing the Stern–Volmer equation and the number of tryptophan residues. The stability of encapsulated resveratrol was evaluated after exposure to ultraviolet A (UVA) light and 3‐stage in vitro digestion. After UVA light exposure, SC‐based microcapsules maintained a higher trans:cis resveratrol ratio (0.63, P < 0.05) than WPC‐based microcapsules (0.43) and unencapsulated resveratrol (0.49). In addition, encapsulation of resveratrol in both protein microparticles led to an increased digestive stability and bioaccessibility in comparison to unencapsulated resveratrol (47% and 23%, respectively, P < 0.05). SC‐based microcapsules provided a higher digestive stability and bioaccessibility (86% and 81%; P < 0.05) compared to WPC‐based microcapsules (71% and 68%). The addition of AMF to the microcapsules did not significantly change the in vitro digestion values. In conclusion, SC‐based microencapsulation increased the stability of trans‐resveratrol to UVA light exposure and simulated digestion conditions. This encapsulation‐system‐approach can be extended to other labile, bioactive polyphenols.     

Structural changes of meat protein of chicken sausages with various levels of salt and phosphate and their effects on in vitro digestion

The objectives of this study were to evaluate protein oxidation and in vitro digestibility of chicken sausages with various salt/phosphate combinations. Hydrophobicity increased when protein was cooked and denatured (P < 0.05). Protein oxidation was increased based on levels of SH, S-S and carbonyl groups during the cooking process (P < 0.05). Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) revealed that the intensity of myosin heavy chain band was decreased while biopolymer band was denser when sausages were cooked. Sausages with 1.8% salt and 0.3% phosphate (S1P1) showed the lowest digestibility and maintained a flat and compact structure, unlike other treatments during the gastrointestinal digestive stage. SDS-PAGE of digested chicken sausages showed that protein bands were degraded into small bands followed by gradual disappearance. In conclusion, cooking process can lead to protein denaturation and oxidation, regardless of levels of salt and phosphate added. In addition, adding salt and phosphate can significantly affect the digestibility of meat products.     

Packaging-specific influence of chitosan on color stability and lipid oxidation in refrigerated ground beef

We examined the influence of chitosan on lipid oxidation and color stability of ground beef stored in different modified atmosphere packaging (MAP) systems. Ground beef patties with chitosan (1%) or without chitosan (control) were packaged either in high-oxygen MAP (HIOX; 80% O₂ + 20% CO₂), carbon monoxide MAP (CO; 0.4% CO + 19.6% CO₂ + 80% N₂), vacuum (VP), or aerobic packaging (PVC) and stored at 1 °C. Chitosan increased (P < 0.05) redness of patties stored in PVC and CO, whereas it had no effect (P > 0.05) in HIOX. Chitosan patties demonstrated lower (P < 0.05) lipid oxidation than controls in all packaging. Control patties in PVC and HIOX exhibited greater (P < 0.05) lipid oxidation than those in VP and CO, whereas chitosan patties in different packaging systems were not different (P > 0.05) from each other. Our findings suggested that antioxidant effects of chitosan on ground beef are packaging-specific.     

复合磷酸盐对鲜切猪里脊肉肌球蛋白凝胶保水性的影响研究

本文研究了焦磷酸钠(SAP)、三聚磷酸钠(STP)、六偏磷酸钠(HMP)及复合磷酸盐对猪肉肌球蛋白凝胶保水性的影响.结果显示:当复合磷酸盐的配比为2:1:1(SAP:STP:HMP),添加量为0.2%时,可获得最佳的感官品质和较好凝胶保水性,影响凝胶保水性因素的主次顺序为SAP＞HMP＞STP,且SAP和HMP对凝胶保水效果具有显著影响.