Soy Isolate Research Articles

Manufacturing of curd products of increased biological value for the elderly from dried components [pdf

BACKGROUND In recent years, the number of elderly people has increased, and the diseases that arise in old age are associated, amongst other factors, with malnutrition. In the elderly, the need for primary nutrients and energy changes, so the development of food products intended for this particular group of people is becom- ing increasingly important. The purpose of this research is to work out the composition of and technology for producing low-fat curd products from raw milk and vegetable components. The developed products can be used for their gerodietetic properties, because nutritional and energy needs in the elderly were taken into account when designing the product. The curd product was manufactured from skimmed dried milk (SDM), soy isolate protein (SIP) and spelt grain. METHODS Optimal conditions for the recombination of SIP were determined. The influence of mass fraction of SIP on the properties of the clot and the end product was studied. The degree of dispersion of the grain component was determined, from the organoleptic evaluation of samples of the mixture, and the optimum method of addition was chosen. The method of adding cooked spelt into the clot after pressing was chosen. Harrington’s generalized desirability function was used for the calculation of the optimum mass frac- tion of the grain component in the end product. RESULTS The formulation and technology for a curd product based on dry ingredients were determined. The amino acid composition and content of essential components in the developed product were determined, and the biological and nutritional value were calculated. CONCLUSIONS The use of dry ingredients for the production of a curd product makes it possible to manufac- ture the product in the absence of raw milk. The formulation of the product is designed taking into account the needs of the body in old age. The incorporation of spelt increases the biological value of the curd product to 81.5%.

A new environmentally friendly bioadhesive mainly modified by propanetriol

In this paper, a series of new environmentally friendly bioadhesives with improved bonding strength were quickly synthesized via urea, sodium dodecyl sulfate (SDS) and propanetriol are mixed with soy isolate protein. The results showed that the bonding strength of the modified adhesives was changed with the increasing content of propanetriol. The maximum dry shear strength of the plywood bonded with the resultant adhesive was increased to 2.45 MPa when the propanetriol content was 20 ml. While the maximum wet shear strength of the plywood bonded with the resultant adhesive arrived 1.32 MPa, which is acceptable for industrial application in plywood fabrication according to the national standards of the People’s Republic of China (≥0.7 MPa). In addition, the orthogonal experiment suggested that the obtained material with pH of 9 for 5 h mixing at the hot pressing temperature of 120 °C exhibited the best comprehensive performance. Also, the FTIR, SEM and DSC measurements showed that the adhesives had a compact structure with stable thermal property.

Impact of food supplements on hemoglobin, iron status, and inflammation in children with moderate acute malnutrition: a 2 × 2 × 3 factorial randomized trial in Burkina Faso

Children with moderate acute malnutrition (MAM) are treated with lipid-based nutrient supplements (LNSs) or corn-soy blends (CSBs) but little is known about the impact of these supplements on hemoglobin, iron status, and inflammation. The objective of this study was to investigate the impact of supplementary foods for treatment of MAM on hemoglobin, iron status, inflammation, and malaria. A randomized 2×2×3 factorial trial was conducted in Burkina Faso. Children aged 6-23 mo with MAM received 500 kcal/d as LNS or CSB, containing either dehulled soy (DS) or soy isolate (SI) and different quantities of dry skimmed milk (0%, 20% or 50% of total protein) for 12 wk. The trial was double-blind with regard to quality of soy and quantity of milk, but not matrix (CSB compared to LNS). Hemoglobin, serum ferritin (SF), serum soluble transferrin receptor (sTfR), serum C-reactive protein (CRP), serum α1-acid glycoprotein (AGP), and malaria antigens were measured at inclusion and after supplementation. Between September 2013 and August 2014, 1609 children were enrolled. Among these, 61 (3.8%) were lost to follow-up. During the 12-wk supplementation period, prevalence of anemia, low SF adjusted for inflammation (SFAI), elevated sTfR, and iron-deficiency anemia decreased by 16.9, 8.7, 12.6 and 10.5 percentage points. Children who received LNS compared to CSB had higher hemoglobin (2 g/L; 95% CI: 1, 4 g/L), SFAI (4.2 µg/L; 95% CI: 2.9, 5.5 µg/L), and CRP (0.8 mg/L; 95% CI: 0.4, 1.2 mg/L) and lower sTfR (-0.9 mg/L, 95% CI: -1.3, -0.6 mg/L) after the intervention. Replacing DS with SI or increasing milk content did not affect hemoglobin, SFAI, sTfR, or CRP. Supplementation with LNS compared to CSB led to better hemoglobin and iron status, but overall prevalence of anemia remained high. The higher concentrations of acute-phase proteins in children who received LNSs requires further investigation. This trial was registered at www.controlled-trials.com as ISRCTN42569496.

Effectiveness of food supplements in increasing fat-free tissue accretion in children with moderate acute malnutrition: A randomised 2 × 2 × 3 factorial trial in Burkina Faso.

BackgroundChildren with moderate acute malnutrition (MAM) are treated with lipid-based nutrient supplement (LNS) or corn-soy blend (CSB). We assessed the effectiveness of (a) matrix, i.e., LNS or CSB, (b) soy quality, i.e., soy isolate (SI) or dehulled soy (DS), and (c) percentage of total protein from dry skimmed milk, i.e., 0%, 20%, or 50%, in increasing fat-free tissue accretion.Methods and findingsBetween September 9, 2013, and August 29, 2014, a randomised 2 × 2 × 3 factorial trial recruited 6- to 23-month-old children with MAM in Burkina Faso. The intervention comprised 12 weeks of food supplementation providing 500 kcal/day as LNS or CSB, each containing SI or DS, and 0%, 20%, or 50% of protein from milk. Fat-free mass (FFM) was assessed by deuterium dilution technique. By dividing FFM by length squared, the primary outcome was expressed independent of length as FFM index (FFMI) accretion over 12 weeks. Other outcomes comprised recovery rate and additional anthropometric measures. Of 1,609 children, 4 died, 61 were lost to follow-up, and 119 were transferred out due to supplementation being switched to non-experimental products. No children developed allergic reaction. At inclusion, 95% were breastfed, mean (SD) weight was 6.91 kg (0.93), with 83.5% (5.5) FFM. In the whole cohort, weight increased 0.90 kg (95% CI 0.88, 0.93; p < 0.01) comprising 93.5% (95% CI 89.5, 97.3) FFM. As compared to children who received CSB, FFMI accretion was increased by 0.083 kg/m2 (95% CI 0.003, 0.163; p = 0.042) in those who received LNS. In contrast, SI did not increase FFMI compared to DS (mean difference 0.038 kg/m2; 95% CI −0.041, 0.118; p = 0.35), irrespective of matrix. Having 20% milk protein was associated with 0.097 kg/m2 (95% CI −0.002, 0.196) greater FFMI accretion than having 0% milk protein, although this difference was not significant (p = 0.055), and there was no effect of 50% milk protein (0.049 kg/m2; 95% CI −0.047, 0.146; p = 0.32). There was no effect modification by season, admission criteria, or baseline FFMI, stunting, inflammation, or breastfeeding (p > 0.05). LNS compared to CSB resulted in 128 g (95% CI 67, 190; p < 0.01) greater weight gain if both contained SI, but there was no difference between LNS and CSB if both contained DS (mean difference 22 g; 95% CI −40, 84; p = 0.49) (interaction p = 0.017). Accordingly, SI compared to DS increased weight by 89 g (95% CI 27, 150; p = 0.005) when combined with LNS, but not when combined with CSB. A limitation of this and other food supplementation trials is that it is not possible to collect reliable data on individual adherence.ConclusionsBased on this study, children with MAM mainly gain fat-free tissue when rehabilitated. Nevertheless, LNS yields more fat-free tissue and higher recovery rates than CSB. Moreover, current LNSs with DS may be improved by shifting to SI. The role of milk relative to soy merits further research.Trial registrationISRCTN registry ISRCTN42569496

Greater Leucine Content Enhances the Acute and Integrated Muscle Protein Synthetic Responses Versus an Isonitrogenous, Isoenergetic Protein Beverage in Healthy Older Women

A decreased anabolic response to protein feeding is one of the mechanisms that underpins sarcopenic muscle loss with aging, with older adults requiring a higher protein dose than younger adults to increase muscle protein synthesis (MPS). Despite this knowledge, a number of commercially available protein beverages targeted to increase protein intake and support lean body mass in older adults contain ≤20 g of protein, and their ability to stimulate MPS in this population is unknown. Leucine has, however, been shown to enhance the MPS response to lower doses of protein and thus may represent an effective ‘anti‐sarcopenic’ ingredient.ObjectiveTo compare the acute and integrated myofibrillar MPS response to a typical commercial protein beverage to that of an isonitrogenous, isoenergetic protein beverage with added leucine in older women.MethodsHealthy, older women (n = 11/group) were recruited and randomized to one of 2 groups: 1) CON: 15 g mixed protein beverage (soy isolate, milk concentrate and caseinate), 2/d; 2) P15: 15 g milk protein concentrate with 4 g leucine (Glanbia Nutritionals, PepForm®), 2/d. Unilateral maximal strength was determined (1‐RM) and one leg was randomized to an exercise condition. For determination of acute MPS, participants underwent a primed constant infusion of 13C6‐phenylalanine and MPS was determined in the fasted, fed (rested) and fed + exercised (4 sets, 50–60% 1 RM, one leg) state. For determination of integrated MPS, participants consumed 100 mL of D2O and MPS was determined prior to (basal) and during 6 d supplementation in the rested and exercised leg. Participants were provided with all food to be consumed throughout the basal and supplementation period, which consisted of 1.0 g/kg/d protein. During the supplementation period the study beverages were incorporated into the diet such that the participant continued to consume 1.0 g/kg/d protein.ResultsAcute MPS was the same in the fasted state in both groups (CON: 0.034 ± 0.001%/h, P15: 0.034 ± 0.001%/h). Feeding increased MPS in the rested (CON: 0.038 ± 0.001%/h, P15: 0.053 ± 0.002%/h) and exercised (CON: 0.043 ± 0.001%/h, P15: 0.064 ± 0.002%/h) leg in both groups, but the increase was greater with P15 (p &lt; 0.001). Integrated MPS was the same in the basal state in both groups (CON: 1.52 ± 0.03%/d, P15: 1.48 ± 0.03%/d). MPS increased with P15 during the supplementation period in both legs (rested: 1.62 ± 0.03%/d, exercised: 1.73 ± 0.03%/d; p &lt; 0.001), but in the exercised leg only with CON (rested: 1.54 ± 0.02%/d, exercised: 1.62 ± 0.02%/d; p &lt; 0.001) and was greater with P15 than CON in both legs (p &lt; 0.001).ConclusionsA protein beverage fortified with 4 g of leucine induced greater increases in acute and integrated MPS than an isonitrogenous protein beverage containing protein equivalent to typical commercially available beverages. As opposed to consumption of P15, which increased MPS, chronic consumption of the CON protein beverage did not increase MPS and thus would not likely attenuate the loss of muscle mass in older adults.Support or Funding InformationPepsiCo Global R&amp;D

Physicochemical and Functional Properties of Protein Isolates Obtained from Several Pea Cultivars

The goal of this research was to investigate the physicochemical and functional properties of protein isolates obtained from several pea cultivars grown at two locations in Canada. The functionalities of the pea protein isolates (PPIs) were then compared with those of commercial food protein ingredients derived from milk, egg, pea, soy, and wheat. Six pea cultivars (Agassiz, CDC Golden, CDC Dakota, CDC Striker, CDC Tetris, and Cooper) were collected from two years over two locations in Saskatchewan (Canada). Samples were evaluated for composition, surface properties, and functional properties. All PPIs had protein levels of ≈91% (db) and isolate and protein yields of ≈18 and ≈72%, respectively. Cultivars exhibited legumin/vicilin ratios from 0.36 (Agassiz) to 0.79 (CDC Golden). Differences among cultivars as well as significant cultivar × environment interactions were found only for maximum intrinsic fluorescence (195–267 arbitrary units), solubility (63–75%), and foaming capacity (167–244%). No differences owing to either cultivar or environment were observed for surface charge (zeta potential = approximately –24 mV), oil holding capacity (≈3.2 g/g), foam stability (≈75%), or emulsion stability (≈96%). Relative to the commercial isolates, PPIs prepared under laboratory conditions behaved most similarly to soy isolates, with the exception of solubility. Whey and egg were superior in solubility and foaming properties, whereas wheat and the commercial pea protein product were significantly lower in nearly all of the functionality tests. Based on their oil holding properties, the laboratory‐prepared PPIs may serve as good meat extenders. The findings also suggest that pea processors may not need to specify either the cultivar or the environment when acquiring raw material, thus creating advantages in their feedstock sourcing.

ВИЗНАЧЕННЯ АМІНОКИСЛОТНОГО СКЛАДУ ТА МІКРОБІОЛОГІЧНИХ ПОКАЗНИКІВ ВАРЕНИХ КОВБАС

Аналіз структури харчування різних груп населення свідчить, що в даний час потреби в білках, в першу чергу тваринного походження, задовольняються лише на 80%.&#x0D; Для досліджень розробили рецептури варених ковбас із заміною частини м’ясної сировини гідратованою білоквмісною харчовою композицією (до 30%) та м’ясом птиці механічного обвалювання (до 30%).&#x0D; Для доведення доцільності використання розробленої композиції у складі варених ковбасних виробів провели визначення амінокислотного складу та вивчили її вплив на термін зберігання готових ковбас шляхом дослідження мікробіологічних показників. Доведено, що спрямоване застосування харчових композицій у технології варених ковбас дозволяє нормалізувати загальний хімічний і амінокислотний склад, забезпечуючи мікробіологічну стабільність готової продукції.&#x0D; Встановлено, що заміна м’ясної сировини ФХК в кількості 30% (характерна для дослідного зразка №1) дозволяє зберегти амінокислотний склад продукту, а додаткове внесення МПМО (характерне для дослідного зразка №2) призводять до його зменшення, особливо таких незамінних амінокислот як ізолейцин та валін.&#x0D; Розроблені композиції сприяють зниженню залишкової мікрофлори та пригнічують зростання мезофільно-аеробних і факультативно анаеробних мікроорганізмів в готових виробах, що пов’язано з їх нижчим початковим мікробіологічним обсіменінням порівняно із м’ясною сировиною.&#x0D;

Optimization of arachidonic acid production from Mortierella alpina PRAO7-10 by response surface methodology

Arachidonic acid (ARA) is an essential fatty acid in animal nutrition. The filamentous fungus Mortierella alpina has been widely used for production of ARA. The strain M. alpina PRAO7-10 was isolated from a soil sample in northern Thailand. Seven parameters—temperature, pH, percentage of medium volume per flask volume (% v/v) and glucose, KNO3, K2HPO4 and soy isolate concentrations—affected the biomass and ARA production of this fungus and were determined using the Plackett-Burman statistical design technique. The results revealed that temperature and % v/v played a significant role in the biomass and ARA production while glucose and soy isolate only affected the ARA production. Therefore, they were chosen for optimization using a central composite design and response surface methodology to maximize the dried cell weight (DCW) and ARA production. The optimal values for the temperature, % v/v, glucose concentration and soy isolate concentration were 25.06 °C, 14.16%, 6.67% and 0.48%, respectively. Under these optimal culture conditions, the maximum DCW and ARA production were 52.64 g/L and 6.76 g/L, respectively. Validation of the optimal conditions showed that deviations in DCW and ARA of the experimental data from the predicted values were 1.72% and 2.42%, respectively, suggesting the suitability of the model employed and that the experimental designs were effective for the optimization of the DCW and ARA production.

Amino acid digestibility of plant protein feed ingredients for growing pigs.

Two experiments were designed to determine the N and AA digestibility of various protein sources (potato protein concentrate, soy protein concentrate, soy protein isolate, linseed meal, sunflower meal, cottonseed meal, canola meal, and camelina meal) fed to growing pigs. In each experiment, barrows were surgically fitted with a simple T-cannula at the distal ileum and fed 4 experimental diets and a N-free diet (NFD) on the basis of a replicated 5 × 2 crossover arrangement with 5 diets and 2 periods. For Exp. 1, 20 cannulated 25-kg barrows received potato concentrate, soy concentrate, soy isolate, and linseed meal. The apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of N for potato concentrate, soy concentrate, and soy isolate were similar and greater than that for linseed meal ( < 0.05). The AID and SID of Leu and Thr were greater in potato protein concentrate than soy concentrate ( < 0.05), and AID and SID of Thr were lower in soy isolate than potato concentrate. The AID and SID of all essential AA were similar between soy isolate and soy concentrate. Linseed meal had the lowest AID and SID of N and AA digestibility among protein sources ( < 0.05). In Exp. 2, sunflower meal, cottonseed meal, canola meal, and camelina meal were fed to 42-kg barrows to determine their AID and SID of AA. The AID and SID of N and all AA were greatest for sunflower meal ( < 0.05), and canola meal had similar AID and SID of N, Met, Thr, Leu, and Val. The AID and SID of all essential AA, except for Met and Trp, were lowest for sunflower meal ( < 0.05). Cottonseed meal had lower AID and SID for Lys, Ile, Leu, Met, Thr, and Val compared with the other protein sources ( < 0.05). In conclusion, the digestibility of N and AA varies greatly among oilseed meals.

Digestive evaluation of soy isolate protein as affected by heat treatment and soy oil inclusion in broilers at an early age.

Soy protein isolate (SPI) mixed with soybean oil (SPIO) incubated at 100°C for 8 h was used to evaluate changes of solubility and digestibility of SPI in vitro and digestive function in broilers at an early age. Arbor Acres broilers were allocated to three groups with six replicates of 12 birds, receiving basal diet (CON), 8 h heat-oxidized SPI diet (HSPI) and 8 h heat-oxidized mixture of SPI and 2% soybean oil diet (HSPIO) for 21 days, respectively. Nitrogen solubility index (NSI) declined and soybean oil accelerated the decline of NSI during incubation (P < 0.05). Decreased in vitro digestibility of dry matter (DM) and crude protein (CP) were observed in SPIO (P < 0.05). HSPI and HSPIO decreased body weight gain, relative jejunum weight and pancreatic trypsin activity at day 21 (P < 0.05). HSPIO decreased anterior intestinal trypsin activity at day 14 and amylase and trypsin activity at day 21, pancreatic amylase activity at day 21 and apparent digestibility of DM, organic matter and CP of broilers from days 18 to 20 (P < 0.05). Heat treatment and soybean oil could induce oxidative modification of SPI, and oxidized SPI negatively affected growth and digestion of broilers. © 2016 Japanese Society of Animal Science.

Evaluation of the acceptability of improved supplementary foods for the treatment of moderate acute malnutrition in Burkina Faso using a mixed method approach

The objective of this study was to evaluate, within the context of a randomized controlled trial of product effectiveness, the acceptability of new formulations of six corn-soy blended flours (CSB) and six lipid-based nutrient supplements (LNS) with different quantities of milk and qualities of soy for the treatment of children with moderate acute malnutrition (MAM).Our study included 1546 children aged 6–23 months and involved questionnaires after one month of supplementation home visits and interviews with a sub-sample of 20 trial participants and their caretakers, and nine focus group discussion.All 12 products were well accepted in terms of organoleptic qualities and received good ratings. However, LNS were more appreciated by caretakers and children. Additionally, an effect of soy isolate was detected on child appreciation where products with high milk content also received better ratings. CSB were not consumed as readily; 33.9% (n = 257) of children receiving CSB were reported to have leftovers compared to 17.3% (n = 134) of children receiving LNS (p=<0.001). Both CSB and LNS were referred to as foods with medicinal properties and perceived as beneficial to child health. They were both reported to have high priority in the daily feeding of the child.In conclusion, there were minimal differences in acceptability of the various CSB and LNS formulations, although CSB were less readily consumed and required smaller meal volumes. Since all products were well-accepted, decisions regarding whether the more expensive products should be used for the treatment of MAM will need to be based on their effect on child nutrition, growth and health. Future supplementary feeding programs in similar contexts could furthermore consider introducing supplementary foods as a medical treatment, as this may increase adherence and decrease sharing.

Clinical reactivity to soy is best identified by component testing to Gly m 8

Soy allergy affects approximately 0.4% of young children in the USA.1 A majority of children with soy allergy become tolerant over time,2 which makes it important that allergists reassess these patients on a regular basis. An accurate assessment of patients with a suspected soy allergy is vital, because avoidance of soy is extremely difficult, it is a common ingredient in processed foods, and consumption of soy-containing food additives (soy isolate, soy concentrate, and soy flour) is increasing in Western diets.

Gelation Property of Alcohol-Extracted Soy Protein Isolate and Effects of Various Reagents on the Firmness of Heat-Induced Gels

Gelation property, thermal property, protein subunits distribution, and molecular forces involved in gelation of alcohol-extracted soy protein isolate were investigated using texture analyzer, differential scanning calorimeter, sodium dodecyl sulfate polyacrylamide gel electrophoresis, and various reagents. Results showed that salts and pH played important roles in gel firmness, and a power law relationship between gel firmness and protein concentration was observed. The effects of various reagents revealed that disulfide bonds play a major role in soy protein gel formation, while the involvement of electrostatic interactions, hydrogen bonds, and/or hydrophobic interactions also occurred in gel networks. Thermal analysis indicated that both alcohol-extracted soy protein isolate and commercial soy protein isolate (isoelectric precipitation) have undergone serious denaturation, while the gel firmness of alcohol-extracted soy protein isolate was significantly greater than that of commercial soy protein isolate. Sodium dodecyl sulfate polyacrylamide gel electrophoresis image showed that there was almost no difference for protein subunits among alcohol-extracted soy protein isolate, commercial soy protein isolate, and soy powder. Hence, as an alternative environmental friendly extraction method, alcohol-extraction of soy protein isolate has a great prospect to replace presently applied isoelectric precipitation method.

Soy-based infant nutrition: a review

Dietary consumption of soy varies worldwide.In Asia, people traditionally consume largequantities of soy, while in Europe, soy is notpart of the traditional or daily eating habits.The USA is a major soy producer. The mean intake ofisoflavones by an adult is 8 - 50 mg/day in Asia but only0.5 - 3.5 mg/day in the Western world.1 The soy intakeof a vegetarian is 3 - 12 mg/day and a vegan achievesan intake of 15-60 mg/day.2In the early 1900s, soy-protein preparationswere the only option for the treatment of cow's milkprotein allergy (CMPA) . The first report of the use ofa soybean -based formula for infants dates from 1909.3Most soy drinks are not enriched with zinc, iron,calcium, phosphorous, methionine, or carnitine. Soydrinks also do not contain soy isolate. Soy productsthat do not fulfill the criteria to be an infant formulaare not adapted for infant feeding.

Improving the Flavor of Soy Ice Cream by Adding Lemongrass or Pandan Leaf Extracts

Lemongrass or pandan leaf extracts were used separately to improve the flavor of soy ice cream. Lemongrass or pandan leaf extracts with water in con- centrations of 10:100, 15:100, and 20:100 w/w were examined using sensory evaluation for the best flavor acceptance. The best ratio was selected to spray dry using maltodextrin as the drying medium at various concentrations (2, 4, 6, 8 and 10% w/w). A ranking preference test was used to determine the flavor of the soy ice cream. Threshold testing was used to determine the sensorial quality of soy isolate protein mixed with both herb extracts, and soy ice cream mixed with both herb extracts. The flavor compound was analyzed by using headspace, solid-phase microextraction, gas chromatography, mass spectrophotometry (HS- SPME-GC-MS). The best concentration of fresh lemongrass or pandan leaf ex- tracts for improving the sensorial flavor of soy ice cream was 10:100 (w/w). The optimum quantity of maltodextrin for spray drying was 2% (w/w). The threshold values of fresh and powdered lemongrass extracts that could mask the beany flavor in soy protein isolate solution and soy ice cream were lower than those of fresh and powdered pandan leaf extracts. The beany flavor in soy protein isolate solution and soy ice cream was mainly composed of hexanal, pentanal, benzaldehyde, 2-pentyl-furan and 1-octen-3-ol. The flavor compounds in pandan leaf extract were 2-acetyl-1-pyroline and 3-methyl-2(5H)-furanone, while those of lemongrass extract were β-myrcene, α-pinene, 3-carene, neral, geranial and geraniol. From the results of HS-SPME-GC-MS, the beany flavor was masked by these extracts. This indicated that lemongrass and pandan leaf extracts could mask the beany flavor and improve the sensorial quality of soy ice cream.

Influence of Dietary Amino Acid Profile on Serum Lipids in Hypercholesterolemic Chinese Adults

To investigate the significance of Lys:Arg and Met:Gly ratio on serum lipids concentrations and adiponectin in hypercholesterolemic adults, 24 g of soy isolate protein supplement (SIP) or milk protein supplement (CON) were randomly given to 90 subjects (n=45/group) daily for 8 weeks. The correlation between dietary proteins, Lys :Arg and Met:Gly ratio and the percentage changes in lipids and adiponectin in 90 subjects were examined. The percentage changes in total and LDL cholesterol concentrations were significantly positively correlated with the ratio of dietary vegetable protein/animal protein (VP/AP) (rs=-0.595, P<0.001 and rs=-0.606, P<0.001 respectively). The changes of total and LDL cholesterol concentrations were significantly correlated with dietary Lys:Arg ratio (rs=0.574, P<0.001 and rs=0.582, P<0.001 respectively). The change in adiponectin was negatively correlated with dietary Lys:Arg and Met:Gly ratio (rs=-0.668, P<0.001 and rs=-0.309, P=0.003 respectively) and was positively correlated with the ratio of VP/AP (rs=0.566, P<0.001). Vegetable protein diet with low Lys :Arg ratio may have a favorable effect on serum total cholesterol, LDL cholesterol and adiponectin.

The Role of Dietary Protein Intake in the Prevention of Sarcopenia of Aging

Sarcopenia is defined as an age-related decrease in muscle mass and performance. Several consensus definitions of sarcopenia exist, each providing different cut points and methodologies for assessing muscle mass and muscle strength. Thus, wide variation in the prevalence of sarcopenia has been reported, generally ranging up to 45% for men and 26% for women. Risk factors for sarcopenia include age, malnutrition, and physical inactivity. Additional evidence suggests a protective role for protein supplementation in older adults to preserve lean body mass and prevent frailty, accepted intervention targets for reducing the risk of sarcopenia. Protein supplements vary widely in their composition, and small trials of heterogeneous study designs have made it difficult to extrapolate findings to develop data-driven, evidence-based recommendations for protein supplementation in sarcopenia prevention. Short-term randomized controlled trials of muscle protein synthesis have demonstrated that whey protein increases synthesis more so than casein or soy isolates. Studies also suggest that essential amino acids stimulate muscle protein synthesis to a greater extent than nonessential amino acids. This review summarizes the epidemiological and clinical trial evidence establishing the current definitions for sarcopenia and provides an overview of the state of the evidence for protein supplementation to prevent and/or mitigate sarcopenia.

High protein diets enhance body composition in rats: a comparative analysis of milk‐and soy‐based energy restricted diets

Consuming high protein diets during energy restriction may protect muscle health. However, the extent to which protein source modulates muscle responses to energy restriction is not well described. Eighty male Sprague‐Dawley rats (12 weeks old) were randomly divided into 8 treatment groups and fed energy adequate (EA) and energy restricted (ER; 60% of the ad libitum feed intake for EA) diets containing two levels (control protein: CP, 10%; and high protein: HP, 35%) and sources (milk protein concentrate: MPC; and isoflavone‐free soy isolate: SOY) of protein for 16 weeks. Body mass was assessed weekly, and fat (FAT) and fat‐free mass (FFM), as percentages of total body mass were determined on weeks 0 and 16 using dual energy x‐ray absorptiometry. Body mass was similar for all rats on week 0, and increased (P &lt; 0.05) linearly independent of protein level and source. Subsequent to week 0, body mass was lower for ER compared to EA (energy‐by‐time, P &lt; 0.05). Protein level influenced FAT and FFM independent of protein source and energy, as FAT was lower and FFM was higher at week 16 for HP compared to CP (P &lt; 0.05). Regardless of protein level and source, FAT was lower and FFM was higher at week 16 for ER than EA (P &lt; 0.05). These data suggest consuming a HP diet may spare FFM and improve body composition independent of energy status, although skeletal muscle responses to milk‐and soy‐based diets are likely comparable. Supported by Dairy Research Institute and USAMRMC

Divergent intramuscular mTORC1 signaling responses to habitual consumption of milk‐and soy‐based energy restricted diets

The effects of milk‐or soy‐based, high‐protein, energy restricted (ER) diets on intracellular regulators of muscle mass are not well described. Eighty male Sprague‐Dawley rats were randomly divided into groups and fed energy adequate (EA) and ER (60% of average ad libitum EA feed intake) diets containing two protein sources (milk protein concentrate: MPC; or isoflavone‐free soy isolate: SOY) and levels (control protein: CP, 10%; high protein: HP, 35%) for 16 weeks. Basal protein expression and phosphorylation of mammalian target of rapamycin complex 1 (mTORC1) associated proteins were assessed using multiplex. Phosphorylation of mTOR was lower (P &lt; 0.05) for ER compared to EA. Independent of protein level, p70S6K1 expression was lower (P &lt; 0.05) for ER MPC compared to EA MPC. However, mTOR and rpS6 protein expression were higher (P &lt; 0.05) for ER SOY than ER MPC, and TSC2, mTOR, and rpS6 were higher (P &lt; 0.05) for ER SOY compared to EA SOY. Phosphorylation of rpS6 was also higher (P &lt; 0.05) for EA SOY compared to EA MPC, and p70S6K1 phosphorylation was higher (P &lt; 0.05) for SOY versus MPC, regardless of energy status and protein level. These data demonstrate divergent mTORC1 responses to soy‐and milk‐based energy restricted diets but suggest that habitual consumption of soy‐based diets may enhance protein synthetic responses to feeding by upregulating the expression of key mTORC1 signaling proteins. Supported by Dairy Research Institute and USAMRMC

Effect of Soy Isolate Protein and Resistance Exercises on Muscle Performance and Bone Health of Osteopenic/Osteoporotic Post-Menopausal Women

There are contradictory reports regarding the effect of soy protein isolate on bone health in menopause. The main objective of this study was to assess the influence of soy isolate protein intake and resistance exercises on isokinetic muscle strength, endurance, power, and bone health parameters in osteopenic/osteoporotic postmenopausal women. Sixty osteoporotic sedentary women (mean age 54.55 years) were randomly assigned to three groups: soy isolate protein (Group A), soy + exercise group (Group B), and control group (Group C). Group B performed supervised progressive resistance exercises 4 times/week for 12 weeks. Muscle performance was measured by isokinetic dynamometry, and bone health was measured by ultrasound densitometry. Analysis of variance showed significant bone and muscle strength gains (p < .05) both in Group A and B, with the improvements more pronounced in Group B. Significant muscle performance changes, after intervention, were evident and bone strength increases may parallel changes in muscle strength.