Effect of milk protein intake and casein-to-whey ratio in breakfast meals on postprandial glucose,satiety ratings,and subsequent meal intake

Whey and casein proteins differentially affect postprandial blood glucose and satiety mechanisms, with relevance for type 2 diabetes and obesity. Therefore, the purpose of this work was to investigate the effect of the casein-to-whey protein ratio and total protein concentration of milks consumed with cereal on postprandial blood glucose, appetite ratings, and subsequent food intake in a randomized, controlled, double-blinded study with healthy young adults (n = 32, 23.4 ± 3.1 yr, body mass index = 22.2 ± 2.5 kg/m²). Fasted participants consumed milk (250 mL) with either 80:20 or 40:60 (modified) casein-to-whey protein ratios at commercially normal (3.1%, wt) or high protein (9.3%, wt) concentration, or control (water with whey permeate), each along with 2 servings of oat-based breakfast cereal. Blood glucose concentrations were determined from finger prick blood samples and appetite was assessed using visual analog scales. Participants consumed a measured ad libitum pizza lunch at 120 min and blood glucose determination and appetite assessment continued following the lunch meal (140–200 min) to observe the second meal effect. Pre-lunch (0–120 min) incremental area under the curve (iAUC) and mean change from baseline blood glucose were reduced with consumption of all milk treatments relative to control. However, we found no differences between all treatments on pre-lunch appetite change from baseline and total area under the curve (tAUC) or lunch meal food intake. In terms of protein concentration results, high protein (9.3%, wt) treatments contrasted to normal protein (3.1%, wt) treatments lowered blood glucose change from baseline and iAUC, and post-lunch appetite change from baseline and tAUC. Protein ratio showed a modest effect in that modified (40:60) protein ratio lowered pre-lunch blood glucose change from baseline but not iAUC, and normal (80:20) protein ratio lowered pre-lunch appetite change from baseline but not tAUC. Therefore, high-carbohydrate breakfast meals with increased protein concentration (9.3%, wt) could be a dietary strategy for the attenuation of blood glucose and improved satiety ratings after the second meal.     

不同黏度魔芋葡甘聚糖对食欲和能量摄入量的影响

目的探讨食品的黏度特性对受试者餐后食欲和能量摄入量的影响。方法通过网络发布3因素进食问卷(three-factor eating questionnaire, TFEQ)招募受试者;以视觉模拟评分法(visual analogue scales, VAS)记录受试者餐后的饥饿感、饱腹感、进食欲望和期望进食量的变化;计算受试者的平均食欲率(meanappetite ratings, MAR)及其食欲的曲线下面积(area under the curve, AUC),并以此作为测试餐饱腹性能的评价指标;为受试者提供随意午餐并记录其进食至完全满足时的能量摄入量。结果同控制组测试餐相比,低、中、高黏度测试餐的饱腹感指数(satiety index, SI)依次达到了127.63%、141.81%和178.43%。并且,与控制组受试者相比,低、中、高黏度组受试者的饱腹感依次提高了31.50%、46.66%和78.63%,饥饿感则分别下降了28.54%、42.92%和60.93%。经不同黏度的测试早餐干预后,在随后的测试午餐实验中,低、中、高黏度组受试者的能量摄入量相比于控制组依次下降了6.69%、10.40%和12.50%。结论食物的黏度对受试者的食欲有显著的影响,一定范围内,食物的黏度越大,其饱腹感指数越大,受试者的饱腹感也随之增加,而饥饿感随之减小。因此,利用魔芋葡甘聚糖(konjacglucomannan,KGM)的高黏特性可以显著提升食物的饱腹性能,从而有效抑制受试者餐后的进食欲望并降低其能量摄入量。     

High Protein Pasta is Not More Satiating than High Fiber Pasta at a Lunch Meal,Nor Does it Decrease Mid‐Afternoon Snacking in Healthy Men and Women

This study compared satiety after high protein pasta (16 g protein, 6 g fiber), high fiber pasta (11 g protein, 8 g fiber) or control pasta (11 g protein, 6 g fiber) in a randomized, placebo‐controlled, double‐blind crossover trial. Participants were 36 healthy and men and women from the University of Minnesota campus. Fasted men and women ate calorie controlled, but macronutrient different pastas at 12:00 pm along with 500 mL of water. The primary outcome was satiety assessed by Visual Analogue Scales at 0, 15, 30, 45, 60, 90, 120, and 180 min daily after consuming the pastas. Secondary outcomes were calories consumed at an ad libitum snack at 3:00 pm, calories from food intake, gastrointestinal tolerance, and palatability. No differences were found among the pasta treatments for satiety, snacking, or gastrointestinal tolerance. Men ate significantly more calories for the rest of the (P = 0.007) after the high protein pasta versus the high fiber pasta (1701 ± 154 compared with 1083 ± 154) with control pasta being intermediate to the other treatments. No significant differences were found for gastrointestinal tolerance, but the palatability ratings showed the high protein pasta was less tasty (P = 0.03) and less pleasant (P = 0.01) than the other 2 pastas. Satisfaction was positively associated with pleasantness and negatively associated with aftertaste. Our results do not support the idea that high protein or high fiber pasta produces a greater satiety response compared to pasta with lower amounts of either nutrient. It is likely that since pasta is already a very satiating food, the subjects were unable to differentiate between the 3 conditions.     

Production of a whey‐based functional beverage supplemented with soy isoflavones and phytosterols

Reconstituted whey beverages were prepared from whey powder by adding either soy isoflavones or phytosterols as functional compounds (at levels of 0%, 0.25%, 0.50% or 1.0% w/v) and probiotic bacteria (Lactobacillus acidophilus LA‐5 or Lactobacillus casei LBC‐81). The addition of nutraceuticals did not change the basic composition of the products. However, a time‐dependent increase in sedimentation/phase separation and acidity of fermented functional beverages was observed. Samples supplemented with phytosterols were more preferred by the panel group than the samples supplemented with isoflavones, and no considerable differences were noted between the control and phytosterol‐added samples in terms of overall perception.     

Concentrate supplementation reduces postprandial plasma ghrelin in grazing dairy cows: a possible neuroendocrine basis for reduced pasture intake in supplemented cows

Ghrelin is an endogenous ligand of the growth hormone secretagogue receptor, and a potent orexigenic agent in human and rodent studies. We hypothesized that ghrelin may play a role in the reduced grazing time in dairy cows receiving supplementary feeds. Fifty-eight Holstein-Friesian (HF) dairy cows of New Zealand (NZ; n = 28) and North American (NA; n = 30) ancestry were provided with unrestricted access to pasture and randomly allocated at calving to either 0, 3, or 6 kg of dry matter concentrates in a 2 × 3 factorial arrangement. Concentrates were offered in equal amounts at each milking. In peak lactation (75 and 79 ± 19.7 d in milk), blood was sampled from all cows prior to the a.m. milking (i.e., baseline) and following 2 h of unrestricted access to fresh pasture after the a.m. milking on 2 consecutive weeks. Daily milk yield and fat, protein, and lactose concentrations were measured on the day of blood sampling. North American cows produced more milk and consumed numerically more pasture than did NZ cows, and NA cows had elevated plasma ghrelin concentrations pre- and postfeeding. A negative association between dry matter intake and postprandial ghrelin concentrations indicated that other controlling factors may be involved. Circulating ghrelin concentrations before feeding were not affected by concentrate supplementation, but increasing supplementation was associated with a linear decline in pasture intake and postprandial ghrelin concentrations. This negative association between concentrate supplementation and plasma ghrelin concentrations offers a potential neuroendocrine basis for the reduced pasture intake when supplements are offered to cows in grazing systems.     

Multiscale design of a dairy beverage model composed of Candida utilis single cell protein supplemented with oleic acid

One of the main challenges in the food industry is to design strategies for the successful incorporation of natural sources of bioactive compounds. Recently, yogurts and other fermented dairy beverages have been proposed as ideal carriers of such bioactive compounds such as fatty acids and antioxidants that could improve consumers' health. However, the incorporation of new ingredients causes functional and structural modifications that may affect the consumers' preferences. In this work, a dairy beverage model supplemented with oleic acid has been designed by partial substitution of milk by Candida utilis single-cell protein extract. The changes in the structural properties of this new beverage were evaluated by following the fermentation process, pH, aggregate size, microstructure, and changes in rheological properties. Furthermore, molecular dynamics simulations were carried out to analyze the interaction between its main components. Our data revealed that samples with a percentage of milk substitution of 30% showed a higher viscosity as compared with the other percentages and less viscosity than the control (no substitution). These samples were then selected for fortification by incorporating oleic acid microcapsules. A concentration of 1.5 g/100 g was shown to be the optimal quantity of microcapsules for oleic acid supplementation. Molecular dynamic simulations revealed glutathione as an important component of the micro-gel structure. The present study forms the basis for novel studies where Candida utilis single-cell protein and microencapsulated essential oils could be used to design innovative bioproducts.     

Metabolic responses of transition Holstein cows fed anionic salts and supplemented at calving with calcium and energy

The objective of this study was to determine the concentrations of plasma Ca, P, Mg, nonesterified fatty acids (NEFA), 3-hydroxybutyrate (BHBA), and glucose in transition cows fed anionic salts prepartum and provided with calcium and energy supplements at calving. The study was conducted on a Florida Holstein dairy farm from November to December 1997. Treatments consisted of no treatment (n = 30); 60 g of Ca as calcium chloride, orally (n = 30); 110 g of Ca as calcium propionate 510 g plus 400 g of propylene glycol, orally (n = 30); two doses of 60 g of Ca as calcium chloride, one at calving and the second 24 h later, orally (n = 30); and 10 g of Ca as borogluconate, intravenously (n = 30). Treatments were administered within 12 h after parturition. Blood samples were collected at d 1 (parturition), 2, 3, 6, 9, and 12 after calving. Plasma total Ca, P, Mg, NEFA, BHBA, and glucose were measured. There were no differences in the concentrations of the blood metabolites among treatments.     

High methoxyl pectin–methyl cellulose films with antioxidant activity at a functional food interface

The effect of using increasing proportions of methylcellulose (MC) for the development of glycerol plasticized films based on high methoxyl pectin (HMP) (30:70, 50:50 and 70:30 w/w HMP:MC) and carrying l-(+)-ascorbic acid (AA) was studied with the purpose of achieving higher stability of AA and localized antioxidant activity at food interfaces. MC and 30:70 HMP:MC systems could not be casted. The shelf-life of the other AA-active films was assessed by storage at 25 °C, constant relative humidity (RH: 33.3%, 57.7% and 75.2%) and vacuum conditions. The rate constant for AA hydrolysis increased with the RH and, hence, with water mobility. Browning and AA degradation rates were directly related. When stored at 75.2% RH, both decreased as MC proportion increased. Compared to HMP film, the highest proportion of MC (50:50 HMP:MC) showed the highest AA stabilization under vacuum and greater performance under air atmosphere. They also developed localized antioxidant activity preserving the tocopherol content of walnut oil.     

Diabetic and non-diabetic consumers' perception of an apple juice beverage supplemented with a Fraxinus excelsior L. seed extract having potential glucose homeostasis benefits

To be successful, an innovative functional food must be perceived by the consumer to present a clear concept and significant health benefit. The main purpose of this study was to evaluate the perception of diabetic and non-diabetic populations to a newly developed beverage containing a Fraxinus excelsior seed extract with previously demonstrated effects on glucose homeostasis in an apple juice. Both the diabetic and non-diabetic populations accepted the health benefits of the functional beverage and no differences were found between their perceptions. No difference was found between perception of both population and specific product information provides a better functional benefits understanding. The consumers made a strong connection between F excelsior seed extract and diabetes in agreement with provided information. Sensory evaluation of the developed functional beverage compared with the apple juice matrix showed that perceived bitterness affected product acceptance and should be corrected.     

Performance and metabolic profile of dairy cows during a lactational and deliberately induced negative energy balance with subsequent realimentation

Homeorhetic and homeostatic controls in dairy cows are essential for adapting to alterations in physiological and environmental conditions. To study the different mechanisms during adaptation processes, effects of a deliberately induced negative energy balance (NEB) by feed restriction near 100 d in milk (DIM) on performance and metabolic measures were compared with lactation energy deficiency after parturition. Fifty multiparous cows were studied in 3 periods (1 = early lactation up to 12 wk postpartum; 2 = feed restriction for 3 wk beginning at 98 ± 7 DIM with a feed-restricted and control group; and 3 = a subsequent realimentation period for the feed-restricted group for 8 wk). In period 1, despite NEB in early lactation [−42 MJ of net energy for lactation (NE_L)/d, wk 1 to 3] up to wk 9, milk yield increased from 27.5 ± 0.7 kg to a maximum of 39.5 ± 0.8 kg (wk 6). For period 2, the NEB was induced by individual limitation of feed quantity and reduction of dietary energy density. Feed-restricted cows experienced a greater NEB (−63 MJ of NE_L/d) than did cows in early lactation. Feed-restricted cows in period 2 showed only a small decline in milk yield of −3.1 ± 1.1 kg and milk protein content of −0.2 ± 0.1% compared with control cows (30.5 ± 1.1 kg and 3.8 ± 0.1%, respectively). In feed-restricted cows (period 2), plasma glucose was lower (−0.2 ± 0.0 mmol/L) and nonesterified fatty acids higher (+0.1 ± 0.1 mmol/L) compared with control cows. Compared with the NEB in period 1, the decreases in body weight due to the deliberately induced NEB (period 2) were greater (56 ± 4 vs. 23 ± 3 kg), but decreases in body condition score (0.16 ± 0.03 vs. 0.34 ± 0.04) and muscle diameter (2.0 ± 0.4 vs. 3.5 ± 0.4 mm) were lesser. The changes in metabolic measures in period 2 were marginal compared with the adjustments directly after parturition in period 1. Despite the greater induced energy deficiency at 100 DIM than the early lactation NEB, the metabolic load experienced by the dairy cows was not as high as that observed in early lactation. The different effects of energy deficiency at the 2 stages in lactation show that metabolic problems in early lactating dairy cows are not due only to the NEB, but mainly to the specific metabolic regulation during this period.     

Output of selenium in milk, urine, and feces is proportional to selenium intake in dairy cows fed a total mixed ration supplemented with selenium yeast

Fifteen rumen fistulated Holstein cows in late lactation and fed a total mixed ration offered ad libitum were supplemented with Se yeast to provide 0, 11, 20, 30, or 42 mg of supplemental Se/day to test the hypothesis that amounts of Se secreted in milk, excreted in urine and feces, and apparently retained in tissues would increase in direct proportion to Se intake. One-half of the yeast supplement was placed directly into the rumen through the fistula of each cow just before milking in the morning and again in the evening, and estimates of average daily excretion of Se were made using total collections of urine and feces from 25 to 31 d after treatments commenced. Amounts of Se secreted daily in milk and apparently retained in tissues increased linearly with average daily intake of Se. The amount of Se excreted in feces and total excretion of Se in urine plus feces increased curvilinearly with Se intake, such that proportionately less Se was excreted as the amount of Se fed increased. On average, total Se excretion accounted for 66%, Se secretion in milk accounted for 17%, and Se apparently retained in tissues accounted for 17% of total Se intake by cows. Thus, in herds fed large amounts of Se yeast, most of the Se will be excreted and retained on-farm. High concentrations of Se will be found where urine and feces accumulate (e.g., yards and effluent ponds), and effluent management practices must be tailored to avoid environmental issues.     

Effect of substituting soybean meal and canola cake with dried distillers grains with solubles at 2 dietary crude protein levels on feed intake,milk production,and milk quality in dairy cows

Dried distillers grain with solubles (DDGS) is an alternative source of feed protein for dairy cows. Previous studies found that DDGS, based on grains other than corn, can substitute for soybean meal and canola cake as a dietary protein source without reducing milk production or quality. As societal concerns exist, and in many areas strict regulation, regarding nitrogen excretion from dairy cows, the dairy industry has focused on reducing dietary protein level and nitrogen excretion. In the present study, we investigated the use of DDGS as a protein source, at a marginally low dietary crude protein (CP) levels, in a grass-clover and corn silage-based ration. The experiment involved 24 Holstein cows and 2 protein sources (DDGS or soybean-canola mixture) fed at 2 levels of CP (14 or 16%) in a 4 × 4 Latin square design. The aim of this study was to evaluate the effect of both protein source and protein level on feed intake, milk yield, and milk quality. The results indicated that feed intake, milk yield, and protein in milk increased when the protein level in the ration was 16% CP compared with 14%. We found no effect of substituting the soybean-canola mixture with DDGS. Moreover, no sensory problems were observed when comparing fresh milk with stored milk, and milk taste was unaffected by DDGS. Milk from cows fed DDGS had a slightly higher content of linoleic acid and conjugated linoleic acid (CLA 9–11), and lower content of C11 to C17 fatty acids than cows fed diets with the soybean-canola mixture. Cows fed the diets with 16% CP produced milk with higher oleic acids and lower palmitic acid content than cows fed 14% CP diets. To conclude, DDGS can substitute for a soybean-canola mixture without affecting feed intake, milk yield and quality, or sensory quality. Under the conditions of this experiment, feeding 16% CP compared with 14% CP in the ration can increase feed intake and milk production.     

Effect of substituting soybean meal and canola cake with grain-based dried distillers grains with solubles as a protein source on feed intake,milk production,and milk quality in dairy cows

The growth of the bioethanol industry is leading to an increase in the production of coproducts such as dried distillers grains with solubles (DDGS). Both corn-based DDGS and grain-based DDGS (gDDGS; defined as originating from grain sources such as barley, wheat, triticale, or a mix, excluding corn) appear to be relevant sources of feed and protein for dairy cows. To date, most of the studies investigating DDGS have been performed with corn-based DDGS. The objectives of this study were to determine the effects of the proportion of gDDGS in the diet on feed intake, milk production, and milk quality. The present experiment involved 48 Holstein cows in a replicated 3 × 3 Latin square design with 3 grass-based dietary treatments consisting of 4, 13.5, and 23% gDDGS on a dry matter (DM) basis (L, M, and H, respectively) as a replacement for a concentrate mix. The concentrate mix consisted of soybean meal, canola cake, and beet pulp. Dry matter intake and energy-corrected milk yield were not affected by the proportion of gDDGS in the diet. Daily milk yield decreased with the H diet compared with the L and M diets. The percentage of fat in milk was higher when cows were fed the H diet compared with the L and M diets, whereas milk fat yield was not affected by dietary treatment. The M diet had a higher percentage of protein in milk compared with the L and H diets. Milk protein yield was similar for the L and M diets; however, it decreased for the H diet. Milk taste was not affected by the proportion of gDDGS in the diet or when milk was stored for 7 d. Linoleic acid and conjugated linoleic acid cis-9,trans-11 in milk increased with increasing proportion of gDDGS. To conclude, gDDGS can replace soybean meal and canola cake as a protein source in the diet of dairy cows. Up to 13.5% of the diet may consist of gDDGS without negatively affecting milk production, milk quality, or milk taste. When gDDGS represents 23% of dietary DM, milk production is reduced by 1.6 kg/d, whereas energy-corrected milk production is numerically reduced by 1 kg.     

Effects of milk replacer meal size on feed intake,growth performance,and blood metabolites and hormones of calves fed milk replacer with or without butyrate ad libitum: A cluster-analytic approach

This study intended to classify ad libitum–fed calves according to their milk replacer (MR) meal size using the K-means clustering approach. This study aimed to investigate the effects of MR meal size on feed intake, growth performance, and blood metabolic and hormones of ad libitum MR-fed calves. German Holstein calves (16 male and 16 female) were studied from birth until d 77 of age. All calves received first colostrum (2.5 kg) milked from their dams within 2 h after birth. Subsequent colostrum meals (subsequent 4 meals until 2.5 d of age; 2 meals/d) and MR (125 g of powder/L; 21.7% crude protein, 18.6% crude fat) were fed ad libitum by teat bucket until d 10 ± 2 of age. Afterward, calves were housed in group pens with automatic feeders for MR (maximum of 25 L/d) and concentrate from 10 ± 3 d of age. Half of the calves received MR supplemented with butyrate to improve growth performance. Milk intake was stepped down to 2 L/d from wk 9 to 10, and 2 L/d of MR were offered until the end of the study. On d 1, 2, 4, and 7, and then weekly until wk 11 of age, blood samples were collected for measurement of metabolites and hormones related to energy metabolism and growth. The K-means cluster analysis on the MR meal size data collected from the automatic feeder resulted in 3 clusters (n = 14, n = 12, and n = 6). Two clusters with a sufficient cluster size (n = 14 and n = 12) were included for further statistical analysis using repeated measures mixed-model ANOVA. In both clusters, butyrate supplementation was equally distributed and failed to affect a difference in MR meal size. Cluster 1 showed calves with higher MR meal size (HI; 2.2 ± 0.11 L/visit of MR) and cluster 2 with lower meal size (LO; 1.8 ± 0.07 L/visit of MR) supplemented MR without (HIB?; n = 6; LOB?, n = 7) or with 0.33% calcium-sodium butyrate (HIB+; n = 6; LOB+, n = 7). Dry matter intake of MR did not differ between HI and LO, but intakes of concentrate and total dry matter tended to be greater in HI than in LO and increased more distinctly in HI than in LO at the end of the study. The average daily gain (g/d) was greater in HI than in LO. Plasma concentrations of total protein (g/L), albumin (g/L), glucose (mmol/L), urea (mmol/L), insulin (µg/L), and glucagon (ng/L) were higher, and the concentrations of insulin-like growth factor I tended to be higher, in HI than in LO calves. Plasma β-hydroxybutyrate was higher in LO than in HI at d 63 and lower in calves fed MR with butyrate at d 77. In conclusion, clustering analysis discriminates 2 main groups of calves with different MR meal size and indicates an effect of MR meal size on solid feed intake, growth performance, and metabolic changes.