| Part One The determination of content of phosphorus in meaning soupBackgroundPhosphorus is an essential element accounting for approximately1%of body weight. Phosphorus is a critical component of cells, tissus and organs. Because phosphorus exists in virtually all living organisms, it is found in most foods. Organnic phosphorus is largely bound in vivo to protein and other intracellular carbon-containing molecules. Phosphorus in plants is most in the form of phytic acid or phytate that hardly absorbed, so the animal food is the major source of phosphorus in human body. Dietary phosphorus intake is700mg to1250mg in healthy people and the various content of phosphorus in food lead to the various burden of phosphorus in human body.The kidney is the major organ to excrete phsophorus, the phosphorus rentention occuring in CKD state late3, which lead to renal osteopathy, secondary and vascular and cardiac valvular calcification is an important risk factor in chronic kidney disease. As an most common food in south of China and Hong Kong and Macao regions, meaning soup, made in primary animal food and other Chinese herbal medicine and simmered for a few hours, is considered to have the ability to recover from diseases and keep healthy for a long time, but the nutritive value and especially the level of phosphorus are not investigated clearly. Study demonstrated that phsophorus can extracted into the water in high temperature.PurperseIn order to provide theoretical direction on modulating dietary structures and improving simmering methods in patients with chronic kidney disease, we analyzed the effect of various materials, simmering time and cooking methods on the level of phosphorus in meaning soup.Methods1. Preparation of meaning soup1.1Materials and prescriptionChoicing the most common three kinds of meaning soup:(1) Pork soup:pork lean500g, asparagus20g, radix rehmanniae recen20g, ginger10g and salt3g;(2) Chicken soup:chicken500g, poria cocos5g, codonopsis5g, radix rehanniae preparata8g, ginger10g and salt3g;(3) Spine soup:pig spine500g, pitaya flower50g, red dates25g, ginger10g and salt3g;1.2Cooking methodsThe soups were made by pork (500g), chicken (500g) or pig spine (500g), and tap water (3000ml) in addition, and simmering for1.5h,3h and6h, respectively.Pre-soaked:The main materials such as pork (500g), chicken (500g) or pig spine (500g), were pre-soaked in boiling water (1000ml) until boiled again, respectively, followed common simmering for3hours in tap water (3000ml). After ten minutes standing at room temperature, the fluid from boiling was calculated volume, filtrated through gaouzes and filter papers, and stored at-20℃until assayed.2Preparation of sample The soups were filtrated through four pieces of gauzes, repeated for three times and one piece of filter papers once, then calculated the volume and mixed sufficiently with magnetic stirring apparatus, the filter was collected in three centrifugal tubes of50ml, and stored at-20℃until assayed.3Determination of phosphorusBy molybdenum blue spectrophotometry10.00ml of liquid sample in tall beaker as well as blank control sample digested at350℃with8.0ml of sulfuric acid96%and2.0ml perchloric acid for0.5to1h until the mixture was clear. Cool digestion was diluted to50ml volumetric flask using pure water. Added10.00ml of sample or blank control sample to colorimetric tubes of50ml, with2.0ml of ammonium molybdate5%(5g of ammonium molybdate dissolved in sulfuric acid4%to100ml) for5minutes to sufficiently react, then added1.0ml of sodium sulfite20%and1.0ml of benzenediol0.5%further. Cool solution was diluted to colorimetric tubes50ml using pure water. The absorbency was made through use of known calibration standard curve after30minutes until the complete reaction.4Determination of crude proteinBy kjeldahl nitrogen determination30.00ml of sample in conical as well as blank control sample digested at350℃with3.0g of copper sulphate and10.0ml of sulfuric acid96%for40minutes to60minutes and600℃for40minutes until the mixture was clear. Cool digestion was diluted to100ml volumetric flask using pure water. Added50ml of sample or blank control sample to Kjeldahl flask, fixed the distillation equipment added10.0ml of boracic acid2%and3to4drip of mixture indicator (methyl red0.1%and bromcresol green0.1%) to the receiving bottle. Followed20.0ml of sodium hydroxide40%to Kjeldahl flask with long tube funnel, and heated at250℃until the solution in the receiving bottle change from light red to light green, stoped distilling after30minutes. Titrated with standard hydrochloric acid0.1mol/1to endpoint (color change from light green to red) and recorded volume.Statistic analysis All variables are expressed as mean±SD. Different time measurement data were analysised by repeated-measurement ANOVA, epsilon correction coefficient were used to adjust degrees of freedom when Mauchly’s test of sphericity were dissatisfied, pairwise comparisons using LSD method for multiple sets of data or two independent samples t-test. Statistical tests were performed with SPSS13.0. The accepted level of significance was P<0.05.Results1. The phosphorus and protein in three kinds of meaning soupThe soups were made by pork (500gram), chicken (500gram) or pig spine (500gram), and tap water (3000ml) in addition, respectively, and simmering for three hours. The concentration of phosphorus (mg/L) was highest in pork soup (401.20±12.30), followed by chicken soup (218.00±5.30) and lowest in spine soup (130.60±2.10)(One-Way ANOVA, F=929.359, P=0.000) as well as content of phosphorus (722.10±16.80,448.70±6.70,239.50±2.30)(P<0.001). There was no significantly differences in content of protein in three soups (P>0.05). The ratio of phosphorus to protein (mg/g) was highest in pork soup (55.43±3.95), followed by chicken soup (32.13±0.29) and lowest in spine soup(17.03±0.44)(One-Way ANOVA, F=212.09, P=0.000).2. The effect of simmering time on phosphorus and protein in three kinds of meaning soupThe soups were made by pork (500g) chicken (500g) or pig spine (500g) and tap water (3000ml) in addition, and simmering for1.5h,3h and6h respectively.2.1The effect of simmering time on level of phosphorus in meaning soupThe concentration of phosphorus (mg/L) increased as the simmering time went on (the pork soup were300.70±22.50,401.20±12.30and591.80±14.80respectively, the chicken soup were175.81±3.28,218.04±5.34and341.23±8.39, respectively, the spine soup were96.25±2.99,130.60±2.09and205.47±3.99, respectively, repeated-measurement ANOVA, P<0.001). But no significant difference was found in the content of phosphorus (repeated-measurement ANOVA, P>0.05).2.2The effect of simmering time on content of protein in meaning soupThe content of protein (g) increased as the simmering time went on (the pork soup were12.41±0.73,13.06±0.74and16.14±1.21, respectively, the chicken soup were10.08±0.23,13.06±0.24and20.54±0.89, respectively, the spine soup were8.57±0.15,14.07±0.33and17.34±0.68, respectively, repeated-measurement ANOVA, P<0.05).2.3The effect of simmering time on ratio of phosphorus to protein in meaning soupThe ratio of phosphorus to protein decreased as the simmering time went on (the pork soup were59.02±0.86,55.43±3.95and46.05±4.43, respectively, the chicken soup were45.23±1.88,32.13±0.29and22.27±0.93, respectively, the spine soup were26.66±0.44,17.03±0.44and13.94±0.77, repeated-measurement ANOVA, P<0.05).3. The effect of pre-soaked treatment on phosphorus and protein in three kinds of meaning soupThe main materials such as pork (500g), chicken (500g) or pig spine (500g), were pre-soaked in boiling tap water (1000ml) until boiled again, respectively, followed common simmering for3hours in tap water (3000ml).3.1The effect of pre-soaked treatment on content of phosphorusAfter pre-soaked, the content of phosphorus (mg) in three soups were558.58±31.19,318.85±11.04and198.42±5.35, respectively, decreased by22.6%,28.9%and17.1%compared with non pre-soaked, respectively (Independent samples T test, P<0.01).3.2The effect of pre-soaked treatment on content of proteinAfter pre-soaked, no significant differences were found in the content of protein in three soups were11.40±1.12,12.93±0.92and12.88±0.66, respectively, decreased by12.7%,1%and8.5%compared with non pre-soaked, respectively (Independent samples T test, P>0.05). 3.3The effect of pre-soaked treatment on ratio of phosphorus to proteinAfter pre-soaked, the ratio of phosphorus to protein (mg/g) in pork soup and chicken soup were46.14±2.73and24.71±0.91,decreased by16.8%,23.1%, respectively (Independent samples T test, P=0.000), the ratio of phosphorus to protein (mg/g) in spine soup decreased by9.4%, but no significant difference was found (P=0.053).Summary:Meaning soup is rich in phosphorus but not protein and have high ratio of phosphorus to protein. Pretreatment with soaking in boiling water can partly remove phosphorus in these materials without having an impact on content of protein, and reduce the content of phosphorus and ratio of phosphorus to protein in the soups. Part two The analysis of water soak to remove the phosphorus in porkBackgroundPhosphorus retention is a common pathophysiological manifestation of chronic kidney disease (CKD), not only occurred in end-stage, but in CKD3period. Hyperphosphatemia, an independent cardiovascular risk factor in CKD, is linked to high mortality. A prospectively clinical trial found that HD Patients with a phosphate level cutoff value greater than6.5mg/dL showed a2.02-fold increase in adjusted RR for mortality compared with those with a normal phosphate level of3.0mg/dL to5.0mg/dL. Kovesdy et al found that a1mg/dl higher time-averaged serum phosphorus was associated with a multivariable adjusted hazard ratio of all-cause mortality of1.56in patients with non-dialysis dependent CKD. Dhingra et al also found that the association between increased serum phosphorus and individuals without chronic kidney disease and cardiovascular disease. But more than50%of patients can’t meet the target level of serum phosphorus that KDIGO recommended.The various phosphate-binders can only remove almost40%of phosphorus. Calcium-containing phosphate-binders overload the calcium after long-term usage of calcium agents especially accompany with vitamin D analogs, which leading to increased risk of vascular calcification, and have an impact on patients’prognosis. Sevelamer removed phosphorus slowly and aggravated metabolic acidosis by consuming bicarbonates in hemodialysis patients. As well as sevelamer hydrochloride, the gastrointestinal side effects and high cost were the limitations of being using widely. Dialysis was a major method to reduce phosphorus in patients with end-stage renal disease, the conventional hemodialysis or peritoneal dialysis can’t eliminate sufficiently to maintain the phosphorus balance. Enhancing dialysis can contribute to remove phosphorus.Walsh et al found that patients on NHD (5to6nights per week for6to10hours per night), had a significant decrease in serum phosphorus by0.49mmol/L compared with conventional hemodialysis after6months. Though significant effect, the high cost leading to discontinuous treatment is an important question for uncontroled hyperphosphatemia.Dietary phosphorus intake is the major source of phosphorus burden in human body. Our former experiment found that most of phosphorus (78%) exreacted into boiling water, even the short time pre-soaked (17.1%-28.9%). study had demonstrated that soaking in warm water in various time could reduce the plant sources of phosphorus. Improving food composition or cooking methods may be a new way to reduce phosphorus burden, but there was no detailed studies about the methods to reduce phosphorus in food until now.PurperseIn order to provide theoretical direction on improving dietary mode in patients with chronic kidney disease, we designed the trial to explore the effect of temperature, time and volume of food in extraction rate of phosphorus and the best way to remove the phosphorus from meat.Methods1. Preparation of experimental pork slice material1.1Material(1) Lots of about200g of fresh pork lean were purchased from the market. Each lot was cut into one lump of approximately6.0cm in longth,6.0cm in wideth and1.6cm in thickeness, which weighed100.0g±2.0g;(2) Repeated (1), divided the100.0g-sampele into two lumps of approximately6.0cm in longth,3.0cm in wideth and1.6cm in thickeness, which weighed50.0g±1.0g;(3) Repeated (2), divided the50.0g-sampele into two lumps of approximately3.0cm in longth,3.0cm in wideth and1.6cm in thickeness, which weighed25.0g±1.0g.1.2Procedure of pre-treatments(1) Placed beakers of2000ml with1000ml pure water in the refrigerator at4℃overnight, until the water temperature reached4℃,100g-samples with the same volume of pork were placed in brakers and allowed to stand in refrigerator at4℃for 1h,2h and4h respectively;(2) Placed beakers of2000ml with1000ml pure water in the room temperature at25℃overnight, until the water temperature reached25℃,100g-samples with the same volume of pork were placed in brakers and allowed to stand at25℃for0.5h,1hour or2h respectively;(3) Placed beakers of2000ml with1000ml pure water in the electrothermostat at50℃for2h, until the water temperature reached50℃,100g-samples with the same volume of pork were placed in brakers and allowed to stand at50℃for5min,15min and30min respectively;(4) Placed1000ml pure water in the electromagnetic oven at100℃until the water boiled,100g-samples with the same volume of pork were placed in electromagnetic oven for0.5min,2.5min and5min respectively.2Preparation of sampleCutting samples of20g to25g into pieces with surgical scissors in beaker of50ml, and dried for three hours in hot air oven at105℃, then removed and grinded it into powder form and dried for three hours. Taken out for grinding, weighting, and then dried for one hour again, repeated the above procedure for ten hours untile the consistent weight, mixed the samples sufficiently and dispensed one-third, sealed for four layers sealing bags and stored at-20℃until assayed.3Determination of phosphorusBy molybdenum blue spectrophotometry1.00g of solid sample in conical flask of250ml as well as blank control sample digested with3.0g of potassium sulphate and20.0ml of sulfuric acid96%at350℃for40minutes to60minutes and600℃for40minutes in electric hot plate until the mixture was clear. Cool digestion was diluted to volumetric flask of100ml using pure water. Added4ml of sample or blank control sample to colorimetric tubes of50ml, with2.0ml of ammonium molybdate5%(5g of ammonium molybdate dissolved in sulfuric acid15%to100ml) for5minutes to sufficiently react, then added1ml of sodium sulfite20%and1ml of benzenediol0.5%further. Cool solution was diluted to50ml using pure water. The absorbency was made through use of known calibration standard curve after30minutes until the complete reaction.4Determination of crude proteinBy kjeldahl nitrogen determination1.00g of sample in conical flask of250ml as well as blank control sample digested at350℃with3.0g of copper sulphate and20.0ml of sulfuric acid96%for40minutes to60minutes and600℃for40minutes in electric hot plate until the mixture was clear. Cool digestion was diluted to volumetric flask of100ml using pure water. Added25ml of sample or blank control sample to Kjeldahl flask, fixed the distillation equipment added10.0ml of boracic acid2%and3to4drip of mixture indicator (methyl red0.1%and bromcresol green0.1%) to the receiving bottle. Followed20.0ml of sodium hydroxide40%to Kjeldahl flask with long tube funnel, and heated at250℃until the solution in the receiving bottle changed from light red to light green, stoped distilling after30minutes. Titrated with standard hydrochloric acid0.1mol/L to endpoint (color changed from light green to red) and recorded volume.5Sensory evaluation5.1Preparation of experimental porkThe pork soaked or not was cut into slices exactly5-mm thick and cooked with moderate salt, monosodium, oil, shallot and paprika for10min on the pan. The cooked pork was served at room tempetature on white plastic dishes marked and stored at4℃for1day until sensory evaluation.5.2The method to sensory evaluationThe6of assessors, blind to sample, were asked to record their intensity scores for mouthfeel (5-point scale with1=very tough or soft and5=crisp), color (5-point scale with1=extremely off color and5=color uniformity), flavor (5-point scale with1=fishy smell and5=extremely aromatic), overall acceptance (5-point scale with1=extremely unlike and5=extremely like).Statistic analysisAll variables are expressed as mean±SD. The effect of primary experimental factor on outcome measurements were analysised by nested-design, the main effect and interaction in secondary and third treatment factors were analysised by2×3factorial analysis, pairwise comparisons using LSD method for multiple sets of data, arcsine square root transformation were made if heterogeneity of variance. The sensory evaluation were analysised by K related samples nonparametric rank test. Statistical tests were performed with SPSS13.0. The accepted level of significance was P<0.05.Results1.The effect of soaked temperatures on phosphorus and protein in pork.The pork (100.0g±2.0g) soaked by various times and volumes of pork in temperatures among4°C,25°C,50°C and100°C respectively. Homogeneity test of variance was satisfied after square root arcsine transformation when Analysising by nested-design ANOVA (Levene’s test F=1.093, P=0.367). After soaked, the average extraction rate of phosphorus was highest in100°C (26.36±8.70), following by25°C (17.85±5.76) and lowest in4°C (14.85±4.50) and50°C(14.55±3.99)(Nest-Design ANOVA, F=125.493, P=0.000). Homogeneity test of variance was satisfied when Analysising by nested-design ANOVA (Levene’s test F=0.825, P=0.731). After soaked, the average extraction rate of protein was highest in100°C (7.55±2.04), following by4°C (6.35±1.28) and50°C (5.72±1.93) and lowest in25°C (5.28±0.87)(Nest-Design ANOVA, F=46.42, P=0.000). Homogeneity test of variance was satisfied after arcsine square root transformation when Analysising by nested-design ANOVA (Levene’s test F=1.014, P=0.467). After soaked, the average decrease ratio of phosphorus to protein was largest in100°C (20.49±7.88), following by25°C (13.30±5.59), and lowest in4°C (9.13±4.07) and50°C (9.43±2.78)(Nest-Design ANOVA, F=87.562, P=0.000).2.The effect of volumes of pork on phosphorus and protein in pork.The pork (100.0g±2.0g) soaked by various temperatures and times in volumes of pork among6.0cm×6.0cm×l.6cm×l,6.0cm×3.0cm×l.6cm×2and3.0cmx3.0cm×l.6cm×4respectively. Homogeneity test of variance was satisfied after arcsine square root transformation when Analysising by nested-design ANOVA (Levene’s test F=1.093, P=0.367). After soaked, the average extraction rate of phosphorus was highest in3.0cmx3.0cmxl.6cm×4(21.68±7.74), following by6.0cmx3.0cm×l.6cm×2(18.19±6.78) and lowest in6.0cm×6.0cm×l.6cm×l (15.33±7.16)(Nest-Design ANOVA, F=64.902, P=0.000). Homogeneity test of variance was satisfied when Analysising by nested-design ANOVA (Levene’s test F=1.825, P=0.731). After soaked, the average extraction rate of protein was highest in3.0cm×3.0cm×l.6cm×4(6.74±1.92), following by6.0cm×3.0cm×l.6cm×2(6.19±1.84) and lowest in6.0cm×6.0cm×l.6cm×l (5.74±1.52)(Nest-Design ANOVA, F=l5.925, P=0.000). Homogeneity test of variance was satisfied after arcsine square root transformation when Analysising by nested-design ANOVA (Levene’s test F=1.041, P=0.467). After soaked, the average decrease rate of phosphorus to protein was largest in3.0cm×3.0cm×l.6cm×4(16.12±7.36), following by6.0cm×3.0cmxl.6cm×2(12.89±6.03) and smallest in6.0cm×6.0cm×l.6cm×l (10.25±6.62)(Nest-Design ANOVA, F=44.723, P=0.000).3. The effect of soaked times on phosphorus and protein in pork.The pork (100.0g±2.0g) soaked by various temperatures (4°C,25°C,50°C and100°C) and pork volumes (6.0cm×6.0cm×l.6cm×l,6.0cm×3.0cm×l.6cm×2and3.0cm×3.0cm×l.6cm×4) in various times. Factorial design ANOVA (Levene’s test F=1.179, P=0.363), in4°C, the average extraction rate of phosphorus was highest in4h (18.81±2.91), following by2h (13.78±3.70) and lowest in lh (11.96±3.92)(Factorial design-ANOVA, F=55.431, P=0.000). Factorial design ANOVA (Levene’s test F=1.187, P=0.360), in25°C, the average extraction rate of phosphorus was highest in2h (22.25±5.28), following by lh (18.41±5.31) and lowest in0.5h (12.89±1.30)(Factorial design-ANOVA, F=50.164, P=0.000). Factorial design ANOVA (Levene’s test F=2.264, P=0.072), in50°C, the average extraction rate of phosphorus was highest in30min (18.25±1.57), following by15min (15.48±1.36) and lowest in5min (9.92±2.64)(Factorial design-ANOVA, F=145.022, P=0.000). Factorial design ANOVA (Levene’s test F=1.773, P=0.149), in100°C, the average extraction rate of phosphorus was highest in5min (34.83±4.08), following by2.5min (27.54±5.92) and lowest in0.5min (16.72±2.73)(Factorial design-ANOVA, F=69.964, P=0.000). Factorial design ANOVA (Levene’s test, F=2.104, P=0.091), in4°C, the average extraction rate of protein was highest in4h (7.66±0.75), following by2h (6.29±0.65) and lowest in lh (5.10±0.80)(Factorial design-ANOVA, F=28.431, P=0.000). Factorial design ANOVA (Levene’s test F=0.558, P=0.798), in25°C, the average extraction rate of protein was highest in2h (6.11±0.58), following by lh (5.24±0.67) and lowest in0.5h (4.50±0.46)(Factorial design-ANOVA, F=14.945, P=0.000). Factorial design ANOVA (Levene’s test F=1.693, P=0.168), in50°C pretreatment, the average extraction rate of protein was highest in30min (7.33±1.74), following by15min (6.19±0.88) and lowest in5min (3.63±0.36)(Factorial design-ANOVA, F=82.434, P=0.000). Factorial design ANOVA (Levene’s test F=1.414, P=0.256), in100°C, the average extraction rate of protein was highest in5min (9.65±1.06), following by2.5min (7.79±0.91) and lowest in0.5min (5.21±0.66)(Factorial design-ANOVA, F=113.725, P=0.000). Factorial design ANOVA (Levene’s test F=1.437, P=0.248), in4°C, the average decrease rate of ratio of phosphorus to protein was highest in4h (12.07±3.08), following by2h (7.99±4.03) and lh (7.34±3.63)(Factorial design-ANOVA, F=20.407, P=0.000). Factorial design ANOVA (Levene’s test F=0.793, P=0.615), in25°C, the average decrease rate of ratio of phosphorus to protein was highest in2h (17.20±5.50), following by lh (13.91±5.37) and lowest in0.5h (8.78±1.41)(Factorial design-ANOVA, F=39.009, P=0.000). Factorial design ANOVA (Levene’s test F=1.892, P=0.125), in50°C, the average decrease rate of ratio of phosphorus to protein was highest in30min (11.77±1.42), following by15min (9.91±0.80) and lowest in5min (6.62±2.69)(Factorial design-ANOVA, F-56.76, P=0.000). Factorial design ANOVA (Levene’s test F=2.150, P=0.085), in100°C, the average decrease rate of ratio of phosphorus to protein was highest in5min (27.86±4.58), following by2.5min (21.45±5.89) and lowest in0.5min (12.15±2.4)(Factorial design-ANOVA, F=43.065, P=0.000).4. Comparison of soaked methods for the largest impact on extraction rate of phosphorus and decrease rate of phosphorus to protein in porkThe pork (100.0g±2.0g) soaked by various times and volumes in temperatures among4°C,25°C,50°C and100°C respectively. We found that groups of4°C+4h+3cm×3cm×l.6cm×4,25°C+2h+3cm×3cm×l.6cm×4,50°C+30min (including6 cm×6cm×l.6cm×l,6cm×3cm×l.6cm×2and3cm×3cm×l.6cm×4),100°C+5min (including6cm×6cm×l.6cm×l,6cm×3cmxl.6cm×2and3cm×3cm×l.6cm×4) had the largest extraction rate of phosphorus among each temperature groups respectively analysised by2×3factorial analysis. Pairwise comparisons using LSD method for multiple sets of these groups (Levene’s test F=2.554, P=0.084), groups of100°C+5min (including6cm×6cm×l.6cm×l,6cm×3cm×l.6cm×2and3cm×3cm×l.6cm×4) showed the largest extraction rate of phosphorus in all groups (34.83±4.08)(one-way ANOVA, F=54.160, P=0.000). Groups of4°C+1h+(6cm×6cm×l.6cm×1or6cm×3cm×l.6cm×2),25°C+0.5h (including6cm×6cm×l.6cm×l,6cm×3cm×l.6cm×2and3cm×3cm×l.6cm×4),50°C+5min+(6cmx6cm×l.6cm×l or6cm×3cm×l.6cm×2),100°C+0.5min+(6cm×6cm×l.6cm×l or6cm×3cm×l.6cm×2) had the smallest extraction rate of protein among each temperature groups respectively analysised by2×3factorial analysis. Pairwise comparisons using LSD method for multiple sets of these groups (Levene’s test, P=0.265), groups of50°C+5min+6cm×6cm×l.6cm×l and50°C+5min+6cm×3cm×l.6cm×2showed the smallest extraction rate of protein in all groups (3.43±0.18)(one-way ANOVA, F=18.109, P=0.000). Groups of4°C+4h+3cm×3cm×l.6cm×4,25°C+2h+3cm×3cm×l.6cm×4,50°C+0.5h (including6cm×6cm×l.6cm×l,6cm×3cm×l.6cm×2and3cm×3cm×l.6cm×4),100°C+5min (including6cm×6cm×l.6cm,6cm×3cm×1.6cm×2and3cm×3cm×l.6cm×4) had the largest decrease rate of ratio of phosphorus to protein among temperature groups of4°C,25°C and100°C respectively analysised by2×3factorial analysis. Pairwise comparisons using Dunnett’s T3method for multiple sets of these groups (Levene’s test, PKI.009), groups of100°C+5min (including6cm×6cm×l.6cm,6cm×3cm×l.6cm×2and3cm×3cm×l.6cmx4) showed the largest decrease rate of ratio of phosphorus to protein in all groups (27.86±4.58)(one-way ANOVA, F’=54.065, P=0.000).5. The effect of soaked methods on the sensory evaluation of cooked porkThe pork (25.0g±1.0g) soaked in various temperatures (4°C,25°C,50°C and100°C) for4h,2h,30min and5min respectively, and used raw pork without any pretreatment as control. The pork soaked or not was cut into slices exactly5-mm thick and cooked with moderate salt, monosodium, oil, shallot and paprika for10min on the pan. We found that the cooked pork soaked in100℃water was tougher than others.(sum rank of23,16.5,22.5,21,7respectively)(Nonparametric Test, F=15.269, P=0.004). There was no significantly difference in color or flavor, the overall acceptance indicated that the methods to remove phosphorus in pork had not an impact on sensory evaluation.Summary:Water soaked can remove the phosphorus from meat without an impact on protein. Soaked in boiling water briefly had the most impact on extraction rate of phosphorus and decrease ratio of phosphorus to protein. The soaked methods had little effects on sensory evaluation.ConclusionWe comfirmed that meaning soup was rich in phosphorus and had high ratio of phosphorus to protein. Soaked in boiling water can only partly reduce phosphorus and ratio of phosphorus to protein in the soups. Water soaked can remove the phosphorus from meat without an impact on protein. Soaked in boiling water briefly had the most impact on extraction rate of phosphorus and decrease ratio of phosphorus to protein. The soaked methods had little effects on sensory evaluation. |
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