Changes in protein nutritional quality in fresh and recombined ultra high temperature treated milk during storage

The objective of this study was to determine the changes in nutritional quality of protein in stored UHT milk. Commercial fresh and recombined ultra high temperature (FUHT and RUHT respectively) treated milk samples were used. Pasteurized milk (P-milk) samples were used for comparison. Milk samples were freeze-dried for the use in diet formulation. Pasteurized milk samples were freeze-dried within 24 h of production. FUHT and RUHT milk samples were freeze-dried after production (zero time), 3 and 6 months of storage at 37 degrees C. Three nitrogen balance experiments were done at zero time, after 3 and 6 months of storage. The diet used in all experiments were similar in composition except for protein source. In each experiment egg white (low protein), casein (control), P-milk, and either 0, 3 or 6 months old FUHT and RUHT milk samples were used as the source of protein in the diets. In each experiment 30 (six for each diet) male Sprague-Dawley rats were used. Apparent digestibility (AD), true digestibility (TD), biological value (BV), and net protein utilization (NPU) were calculated for protein in casein and all milk samples. The nutritional quality of protein in FUHT milk before storage was similar to that of protein in pasteurized milk, but it decreased during storage for 3 months and then remained at the same quality up to 6 months of storage. BV and NPU of protein in FUHT milk after storage for 3 and 6 months were lower than that of protein in pasteurized milk by 4% (not significant) and 5% respectively. On the other hand, the nutritional quality of protein in RUHT milk before storage was lower than that of protein in pasteurized milk and remained at the same level after storage for 3 months: however, it decreased significantly after storage for 6 months. AD and TD of protein in RUHT milk stored for 6 months were lower than that of protein in pasteurized milk by 5% and BV and NPU were lower than that of protein in pasteurized milk by 9 and 12% respectively. The above reduction in nutritional quality of protein in UHT milk may be of significant value in feeding young children who might be dependent on this type of milk in their diet.     

Microbiological Evaluation of Ultra-High-Temperature (UHT)-Treated Milk Close to Expiry Date and Routine Home Practices for Preservation of Milk

Background:

As milk is an excellent medium for growth of microorganisms, milk gets contaminated very easily leading to its early spoilage and to milk-borne diseases.

Objectives:

To compare the quality of pasteurized milk with milk cooker-treated milk and to compare the quality of fresh ultra-high-temperature (UHT) milk with that of UHT milk close to expiry date.

Materials and Methods:

Samples of pasteurized milk, milk heated in milk cooker, fresh UHT milk, and UHT milk nearing expiry date were tested by methylene blue reduction test, coliform test, and colony count test. The results were analyzed statistically using Statistical Package for Social Sciences (SPSS) version 11.5.

Results:

All milk samples passed the methylene blue test and UHT-treated milk passed the coliform test also. Out of the 30 fresh pasteurized milk samples, seven (23.3%) passed the coliform test; but the same after milk cooker treatment, 16 (53.3%) passed the coliform test (P < 0.05). Fourteen (46.6%) out of 30 fresh pasteurized milk samples failed the colony count test, but the same after milk cooker treatment only eight (26.6%) failed the test (P = 0.583). Only seven out of the 60 UHT milk samples failed the colony count test and out of these six (20%) were close to expiry date (P < 0.05).

Conclusions:

Milk cooker-treated milk appears to be safer than the fresh pasteurized milk. Fresh UHT-treated milk is safer then UHT milk close to expiry date.     

In vitro evaluation of iron solubility and dialyzability of various iron fortificants and of iron-fortified milk products targeted for infants and toddlers

The objectives of the present study were: to compare the solubility and dialyzability of various iron fortificants (iron pyrophosphate, ferrous bis-glycinate, ferrous gluconate, ferrous lactate, ferrous sulfate) added, in the presence of ascorbic acid, to pasteurized milk samples produced under laboratory conditions; and to compare the solubility and dialyzability of iron in commercial pasteurized, UHT and condensed milk products available in the Greek market fortified with various vitamins and minerals including iron and targeted towards infants (6-12 months old) and toddlers. Iron solubility and dialyzability were determined using a simulated gastrointestinal digestive system. Ferrous dialyzable iron (molecular weight lower than 8000) was used as an index for prediction of iron bioavailability. Ferrous dialyzable iron in pasteurized milk samples fortified with iron pyrophosphate, ferrous lactate and ferrous bis-glycinate was higher (P < 0.05) than that in milk samples fortified with ferrous sulfate and ferrous gluconate. In commercial liquid pasteurized or UHT milk products, formation of ferrous dialyzable iron in products fortified with ferrous lactate was not different (P > 0.05) from those fortified with ferrous sulfate. Ferrous dialyzable iron in four condensed commercial milk products was higher (P < 0.05) than the corresponding values of the liquid UHT milk samples fortified with the same fortificant (ferrous sulfate). Ferrous dialyzable iron was higher (P < 0.05) in products targeted for infants compared with those targeted for toddlers. In conclusion, the type of iron source, milk processing and the overall product composition affect formation of ferrous dialyzable iron and may determine the success and effectiveness of iron fortification of milk.     

In vitro evaluation of iron solubility and dialyzability of various iron fortificants and of iron-fortified milk products targeted for infants and toddlers

The objectives of the present study were: to compare the solubility and dialyzability of various iron fortificants (iron pyrophosphate, ferrous bis-glycinate, ferrous gluconate, ferrous lactate, ferrous sulfate) added, in the presence of ascorbic acid, to pasteurized milk samples produced under laboratory conditions; and to compare the solubility and dialyzability of iron in commercial pasteurized, UHT and condensed milk products available in the Greek market fortified with various vitamins and minerals including iron and targeted towards infants (6–12 months old) and toddlers. Iron solubility and dialyzability were determined using a simulated gastrointestinal digestive system. Ferrous dialyzable iron (molecular weight lower than 8000) was used as an index for prediction of iron bioavailability. Ferrous dialyzable iron in pasteurized milk samples fortified with iron pyrophosphate, ferrous lactate and ferrous bis-glycinate was higher (P?<?0.05) than that in milk samples fortified with ferrous sulfate and ferrous gluconate. In commercial liquid pasteurized or UHT milk products, formation of ferrous dialyzable iron in products fortified with ferrous lactate was not different (P?>?0.05) from those fortified with ferrous sulfate. Ferrous dialyzable iron in four condensed commercial milk products was higher (P?<?0.05) than the corresponding values of the liquid UHT milk samples fortified with the same fortificant (ferrous sulfate). Ferrous dialyzable iron was higher (P?<?0.05) in products targeted for infants compared with those targeted for toddlers. In conclusion, the type of iron source, milk processing and the overall product composition affect formation of ferrous dialyzable iron and may determine the success and effectiveness of iron fortification of milk.     

Nutritional Adequacy of Commercial Infant Milk Formulas

The nutritional adequacy of six commonly consumed commercial infant milk formulas were evaluated chemically and biologically in growing rats. Infant formulas (per 100 kcal) provided protein (2.2-2.6 g), fat (4.9-5.4 g), available carbohydrates (10.3-11.4 g), Ca (62.5-80.8 mg), P (31.3-66.1 mg), Fe (0.7-1.8 mg), Zn (0.5-0.8 mg), and Cu (0.05-0.08 mg). The energy density varied between 503 and 526 kcal/100 g. Higher levels of linoleic and saturated fatty acids than in human milk were found. Methionine, tryptophan and lysine were the first, second, and third limiting amino acids in all infant formulas. The true protein digestibility (TD), net protein utilization (NPU), biological value (BV) and utilizable protein (UP) varied from 93-96%, 0.75-0.79, 80-82% and 8.7-10.5% respectively. The protein quality of infant formulas was lower than in cow's milk and human milk.     

Diet and disadvantage: observations on infant feeding from an inner city

Background: There are few detailed nutritional studies analysing dietary intakes and weaning practices of inner city infants aged 0–12 months. Pasteurized cow's milk (PCM) is not recommended as a main drink until after 1 year of age, although early usage is still common. Premature introduction of pasteurized cow's milk is associated with increased risk of iron deficiency anaemia. Methods: We therefore prospectively examined the dietary effect of early introduction of pasteurized cow's milk on the nutritional intake of 100 infants (mean age at recruitment 7.8 months), whose mothers had already elected to introduce cow's milk before the recommended age of 12 months in a deprived inner city area. In addition, a retrospective questionnaire on feeding practices and food choices was administered and information on parental education and employment was collected, together with a 3-day dietary diary of weighed intakes at recruitment. Results: The results indicate that weaning practices are handed down from family and friends and are intuitive rather than informed. Over 80% of the infants had intakes of iron, zinc and vitamin D below the reference nutrient intake (RNI) and a further 41% had low vitamin C intakes. Prior to introduction of PCM, there was also misuse of infant formula. Twenty per cent added an extra scoop of powder to the feeds, 10% added milk powder to the bottle before addition of water and 30% used microwave ovens to heat the infant bottle. Conclusion: Feeding practices in a deprived inner city area differed substantially from guidelines and infants were at risk of developing nutrient deficiencies as well as poor feeding practices.     

Vitamins,fatty acids,and antioxidant capacity stability during storage of freeze-dried human milk

Although freezing is the most common method used to preserve human milk, nutritional and immunological components may be lost during storage. Freeze-drying could increase the shelf life of human milk, while preserving its original characteristics. Seventy-two samples of freeze-dried human milk were stored for different periods of time, up to a maximum of 3?months, at 4?°C or 40?°C. Vitamin C, tocopherols, antioxidant capacity, and fatty acids composition were analyzed. A new HILIC–UHPLC method improving vitamin C determination was also validated. Ascorbic acid and total vitamin C concentrations significantly decreased at both temperatures, while antioxidant capacity only decreased at 40?°C. Fatty acids composition and both γ-tocopherol and δ-tocopherol contents remained unaltered. The stability after storage of freeze-dried milk was higher than that reported for frozen or fresh milk indicating that freeze-drying is a promising option to improve the preservation of human milk in banks.     

The protein quality of instant blends for infants and children based on milk or cereals and milk

The protein quality of industrially produced and home prepared milk or cereal-milk based foods for infants and children were evaluated by means of biological assays. The net protein utilization (NPU) values of human milk substitutes based on cow's milk varied between 75 and 78 and the NPU of a soy-based product was found to be 70. Cereal-milk based precooked gruel powders had NPU values of 69 to 77. Furthermore, a comparison between industrially processed products and their corresponding home prepared alternatives was made. Although the protein nutritional products, i.e., including the vitamine and mineral content, is more standardized due to supplementation. The NPU assays of some cereal-milk based porridge powders revealed a wide variations (28 to 69); the lowest NPU values reflect the influence of the processing technique. This illustrates the necessity of performing biological evaluations of processed foods.     

Effect of fiber-rich brown seaweeds on protein bioavailability of casein in growing rats

The effect of three subtropical fiber-rich brown seaweeds, Sargassum hemiphyllum (Turn.) C. Ag., Sargassum henslowianum C. Ag. and Sargassum patens Ag., on protein bioavailability of casein were evaluated by growing rats. The effect of the fiber-rich seaweeds was determined by comparing the net protein ratio (NPR), true protein digestibility (TD), nitrogen balance (NB), biological value (BV), net protein utilization (NPU), and fecal and urinary nitrogen loss of seaweed-based diet groups with those of the cellulose-based control group. There were no significant differences on NPR and urinary N loss in all diet groups. However, the values of TD (range 85.6-89.6%), BV (range 96.9-97.5%), NPU (range 83.5-86.8%) and NB (range 145-150 mg/rat/day) in all seaweed-based diet groups were significantly (p<0.05, one-way ANOVA, Tukey-HSD) lower than those of the control group. On the contrary, the fecal weight (range 5.59-6.30 g/rat/day) and fecal nitrogen (N) loss (range 31.1-41.2 mg/rat/day) of rats fed seaweed-based diets were significantly (p<0.05, one-way ANOVA, Tukey-HSD) higher than that of the control one. However, the differences on the body weight gain and weight of internal organs including liver, kidney and spleen between the seaweed-based diets and control groups were insignificant except that the weight of caecum of rats fed seaweed-based diets was significantly (p<0.05, one-way ANOVA, Tukey-HSD) higher than that of control group. The possible mechanism of fiber-rich brown seaweeds in affecting the protein bioavailability of casein and their related nutritional implications were discussed.     

Taurine in milk and yoghurt marketed in Italy

Taurine, a free amino acid, was studied as natural compound of different typologies of milk: pasteurized, ultra-high temperature (UHT), microfiltered whole and semi-skimmed cow's milk; pasteurized and UHT goat's whole milk and raw buffalo's whole milk. Moreover, taurine contents in yoghurt from cow and goat's milk were evaluated. The data obtained in this research showed that no significant variations of taurine occurred in cow's milk subjected to different technological processes and between whole and semi-skimmed milk. The amount of taurine was less (p < 0.05) in cow's milk (0.60 mg/100 g) than in goat and buffalo's milk (6.55 and 7.32 mg/100 g, respectively). No significant differences in taurine occurred between goat and buffalo's samples. The amounts of taurine in yoghurt reflected, substantially, the content of this molecule in the milk of the relevant animal species. These results are noteworthy because data available in the literature on this molecule in commercial dairy products are old or few.     

Effect of pectin structure on protein utilization by growing rats

The effect of pectins' molecular weight (MW) and degree of esterification (DE) on apparent digestibility (D), net protein utilization (NPU) and biological value (BV) of casein were tested. The pectins prepared differed in MW and DE respectively as follows: P-1 (180,000, 73%); P-2 (300,000, 28%); P-3 (60,000, 74%) and P-4 (75,000, 40%) and were fed as 10% of a purified diet containing 10% casein to growing male rats for 10 days. All preparations decreased D, with P-2 and P-4 showing milder effects than P-1 or P-3. Increased NPU was observed with pectins of low NW and/or DE, being significant only with P-4. Diets containing P-2, P-3 or P-4 had higher BV for casein than the pectin-free diet. Feeding these pectins in a protein-free diet did not cause a significant change in the rats' body N content. Thus, the increase in the BV of casein was attributed to improvements in the pattern of amino acids absorbed by rats fed pectins with low MW and/or low DE.     

Folic acid and 5-methyltetrahydrofolate in fortified milk are bioaccessible as determined in a dynamic in vitro gastrointestinal model

Dairy products are a potential matrix for folate fortification to enhance folate consumption in the Western world. Milk folate-binding proteins (FBP) are especially interesting because they seem to be involved in folate bioavailability. In this study, folate bioaccessibility was investigated using a dynamic computer-controlled gastrointestinal model [TNO gastrointestinal model (TIM)]. We used both ultrahigh temperature (UHT)-processed milk and pasteurized milk, differing in endogenous FBP concentrations and fortified with folic acid or 5-methyltetrahydrofolate (5-CH(3)-H(4)folate). To study FBP stability during gastrointestinal passage and the effect of additional FBP on folate bioaccessibility, FBP-fortified UHT and pasteurized milk products were also tested. Folate bioaccessibility and FBP stability were measured by taking samples along the compartments of the gastrointestinal model and measuring their folate and FBP concentrations. Folate bioaccessibility from folic acid-fortified milk products without additional FBP was 58-61%. This was lower (P < 0.05) than that of the 5-CH(3)-H(4)folate-fortified milk products (71%). Addition of FBP reduced (P < 0.05) folate bioaccessibility from folic acid-fortified milk (44-51%) but not from 5-CH(3)-H(4)folate-fortified milk products (72%). The residual FBP levels in the folic acid- and 5-CH(3)-H(4)folate-fortified milk products after gastrointestinal passage were 13-16% and 0-1%, respectively, of the starting amounts subjected to TIM. In conclusion, milk seems to be a suitable carrier for folate, because both folic acid and 5-CH(3)-H(4)folate are easily released from the matrix and available for absorption. However, our results suggest that folic acid remains partly bound to FBP during passage through the small intestine, which reduces the bioaccessibility of folic acid from milk in this model.     

The source of Yersinia spp. in pasteurized milk: an investigation at a dairy

Pasteurized bottled milk supplied by a single dairy was frequently found to be contaminated with Yersinia spp. Investigations were carried out at the dairy in an effort to pinpoint the source of these organisms. Viable counts obtained from milk bottle rinses indicated that bottle washing was often unsatisfactory, and on one occasion Y. frederiksenii was isolated from the pooled rinse water of six bottles. Samples of milk were taken on arrival at the dairy and at various stages following pasteurization. Heat resistance tests carried out on strains of yersinia isolated from pasteurized milk indicated that they would not survive the pasteurization process. However two strains of yersinia were isolated from a sample of milk taken immediately after pasteurization but before bottling. The thermograph indicated that the time/temperature conditions applied during pasteurization were adequate. The presence of yersinia strains in the milk at this stage therefore suggests that undetectable levels of raw milk were being allowed to contaminate the pasteurized milk. The absence of yersinia in cartoned samples produced on the same day as contaminated bottled samples indicated that environmental contamination of the bottle filler valve also may have occurred at times. Results of this investigation indicate that increased vigilance is required to ensure proper operation of pasteurizers and bottle washers.     

The effect of varying crude protein level and the proportions of fibre in diets containing a mixture of meat-and-bone meal and wheat bran as the only protein source on nitrogen balance indices and energy digestibility in the rat

1. The experiment was designed to investigate the effect of protein level in diets on apparent protein digestibility (AD), true protein digestibility (TD), biological value (BV), net protein utilization (NPU) and energy digestibility (DE) in rats. The design involved fourteen dietary treatments in which a combination of wheat bran and meat-and-bone meal (1:1, w/w dry matter (DM) basis) was the only nitrogen source. Crude protein (N x 6.25; CP) level ranged from 60 to 329 g/kg DM in approximately even increments. All diets contained a constant level of minerals and vitamins. The balance of the diet consisted of a N-free mixture. 2. AD increased from 0.602 at 60 g CP/kg DM to 0.702 at 120 g CP/kg DM, with little change at the higher levels of dietary protein. The fitting of a curve indicated an asymptote of 0.721. 3. TD did not vary significantly between 60 and 225 g CP/kg DM (mean 0.781). At the higher protein levels there was a slight but significant reduction in the mean value (0.758). 4. BV increased from 0.475 at 60 g CP/kg DM to 0.498 at 80 g CP/kg DM where it plateaued, and then from 160 g CP/kg DM it decreased at an increasing rate to 0.216 at 329 g CP/kg DM. 5. The response in NPU closely reflected that obtained with BV, rising from 0.370 to 0.384, then declining to 0.162 at the highest CP concentration. 6. DE decreased linearly from 0.851 at 60 g CP/kg DM to 0.617 at 329 g CP/kg DM. 7. The results confirmed that AD values should only be compared at a defined protein level. TD was essentially independent of dietary CP level, except for a small reduction above 250 g CP/kg, whereas BV and NPU were stable only within the range 80-140 g CP/kg DM. DE was negatively related to dietary CP and fibre level.     

山羊奶粉蛋白质营养价值的评价

本文以成分分析、大鼠实验评价国产山羊奶粉蛋白质的营养价值,并与牛奶粉蛋白质和大豆蛋白进行比较。山羊奶粉蛋白质的主要限制氨基酸是含硫氨基酸,氨基酸分(AS)和化学分(CS)分别为0.91和0.52,其氨基酸模式与牛奶粉蛋白质相近,稍优于酪蛋白,远优于大豆蛋白;蛋白质功效比值(PER)、净蛋白质比值(NPR)、表观消化率(AD)、真消化率(TD)、生物价(BV)和蛋白质净利用率(NPU)分别为3.01、4.62、90.49％、96.75％、86.02和83.22％,除AD稍高外,其他指标均与牛奶粉蛋白质无差别,除PER外各项指标均高于酪蛋白,所有指标均远高于大豆蛋白质。实验结果证实山羊奶粉蛋白质具有和牛奶粉蛋白质一样优良的营养价值。     

Growth and survival of Escherichia coli O157:H7 during manufacture and storage of Indian cheese (paneer)

The growth and survival of Escherichia coli O157:H7 during manufacture and storage of Indian cheese or paneer was investigated. Pasteurized and raw milk that had been inoculated with 10(4) CFU/mL of E. coli O157:H7 cultures were used for manufacturing paneer samples which were vacuum-packaged and stored at 4 degrees C, 8 degrees C, and 28 degrees C. Survival and growth of E. coli O157:H7 in paneer samples was determined after every 4 h for up to 48 h. Escherichia coli O157:H7 could survive the manufacturing process of paneer and were present at the end of the storage period (at 28 degrees C) in significantly (p < 0.05) greater numbers than the initial inoculum. No significant difference in survival and growth were noticeable in paneer samples manufactured from raw milk. Though refrigeration (4 degrees C or 8 degrees C) effectively inhibited the growth of E. coli O157:H7, this pathogen could survive over a period of 48 h. Our observations suggest that unpasteurized or improperly pasteurized milk could be an important source for transmission of E. coli O157:H7 through paneer, and appropriate steps must be taken by government agencies to ensure consumer safety for this dairy product.     

Nutritional and sensory evaluation of tempe-fortified maize-based weaning foods

Maize-based weaning foods prepared from whole maize meal or dehydrated fermented maize (ogi) flour fortified with soybean, cowpea or groundbean tempe, with or without the addition of melon seed flour were fed to 40 albino weanling rats. The nutrient quality of the weaning foods was monitored by the measurement of protein efficiency ratio (PER), net protein ratio (NPR), true digestibility (TD), biological value (BV) and net protein utilization (NPU). Amino acid composition and amino acid scores were determined. The weaning foods were also evaluated for sensory properties and acceptability by nursing mothers and their children. Protein efficiency ratio, net protein retention and net protein utilization of the fortified weaning foods were not significantly different (P > 0.05) when compared to casein diet (control). True digestibility of tempe-fortified maize-based weaning foods averaged 85.4 +/- 3.4% compared to 94.4%, for casein diet. Results from sensory analysis showed that relative to tempe-fortified maize-based weaning foods, most mothers preferred Cerelac, a commercial weaning food, and its porridge because of its vanillic flavour and sweet taste. Despite the low scores recorded for aroma and taste of tempe-fortified maize-based weaning foods, most mothers and their children found porridges prepared from these foods acceptable, with a preference for ogi fortified with cowpea tempe. Tempe-fortified maize-based weaning foods had high protein quality and can support the growth of infants in developing countries especially during the critical weaning period (6-12 months). They were comparable to Cerelac, a commercial baby food in colour and texture.     

江门市新会区乳母成熟乳主要营养成分分析

目的:了解江门市新会区乳母成熟乳主要营养成分的含量与不同年龄、产次、分娩方式的差异。方法:收集江门市新会区1 250例孕足月产后42天乳母的乳汁20 ml,检测标本中的主要营养成分蛋白质、脂肪、乳糖的含量、并与参考值标准进行比较,统计其达到参考值的百分比;统计分析不同年龄段、分娩方式、产次乳母的成熟乳主要营养成分的差异。结果:新会区乳母成熟乳中乳糖、蛋白质含量稳定,均达到或高于参考值;脂肪含量不稳定,34.7%达参考值,3.6%高于参考值,61.8%低于参考值;20～29、30～34及≥35岁3个年龄段和初产妇与经产妇、顺产及剖宫产乳母乳汁主要营养成分差异无统计学意义(P>0.05)。结论:新会区乳母营养状况总体良好,但乳汁中脂肪的含量不稳定,低于参考值的比例较大,应广泛开展针对乳母的膳食营养指导,进一步改善乳母乳汁质量;新会区产妇成熟乳主要营养成分不受乳母年龄、产次、分娩方式的影响,提倡所有健康产妇产后坚持哺乳4～6个月以上。     

Net protein utilization determined by rat bioassay of a protein hydrolysate and a diet for children with phenylketonuria

In a previous study (Kindt et al. 1983, 1984) it was assumed that a protein hydrolysate, devoid of phenylalanine, together with intact protein as given to children with phenylketonuria (PKU), was equivalent to egg or milk protein. One group of children was given this 'PKU protein' in amounts corresponding to the Joint FAO/WHO ad hoc Expert Committee (1973) recommendations. The results indicated that the Joint FAO/WHO ad hoc Expert Committee (1973) recommended levels of protein intake were marginal. The purpose of the present study was to evaluate whether the quality of the protein hydrolysate, together with intact protein ('PKU protein'), is equivalent to egg or milk protein. This was done using a rat bioassay. Four protein sources were used: (1) egg protein, (2) protein hydrolysate, (3) protein hydrolysate diluted with non-essential amino acids, (4) protein hydrolysate mixed with food proteins ('PKU protein'), comparable with the diet previously used (Kindt et al. 1983, 1984). The results indicated that the 'PKU protein' was of very high quality: net protein utilization (NPU) greater than 90. The protein hydrolysate alone and the protein hydrolysate diluted with non-essential amino acids gave a NPU greater than 80. The conclusion drawn from the present study is that the 'PKU protein', as used in the treatment of children with PKU, is equivalent to egg or milk protein. This supported the view that the Joint FAO/WHO ad hoc Expert Committee (1973) recommended levels of intake were marginal.     

陕西澄城县农村乳母膳食与乳汁营养素的调查分析

目的 了解陕西农村哺乳期乳母膳食和乳汁营养素的状况。方法 采取整群抽样的方法，对陕西澄城县农村乳母进行膳食调查、身体营养状况和乳汁营养素测定。运用CDGSS3.0营养软件计算膳食成分，利用SPSS11．0软件进行统计学处理。结果 陕西澄城县农村乳母膳食能量和蛋白质，尤其是优质蛋白质摄人严重不足；乳母身体消瘦发生率为23．64％；乳汁中蛋白质偏低而乳糖偏高；乳汁中能量与乳脂的变化一致；膳食和乳汁中相对应的营养素和能量相关系数差异无显著性。结论 在今后的农村工作中，应加快提高农村生活水平，加强乳母营养知识的教育，改善乳母的膳食营养状况。