Physico-chemical and Textural Properties of 3D Printed Plant-based and Hybrid Soft Meat Analogs.

This study investigated the physico-chemical and textural properties of 3D-printed pea protein-only and pea protein-chicken-based hybrid meat analogs. Both pea protein isolate (PPI)-only and hybrid cooked meat analogs had a similar moisture content of approximately 70%, which was similar to that of chicken mince. However, the protein content increased significantly with the amount of chicken in the hybrid paste undergoing 3D printing and cooking. Significant differences were observed in the hardness values of the non-printed cooked pastes and the 3D printed cooked counterparts, suggesting that the 3D printing process reduces the hardness of the samples and is a suitable method to produce a soft meal, and has significant potential in elderly health care. Scanning electron microscopy (SEM) revealed that adding chicken to the plant protein matrix led to better fiber formation. PPI itself was not able to form any fibers merely by 3D printing and cooking in boiling water. Protein-protein interactions were also studied through the protein solubility test, which indicated that hydrogen bonding was the major bonding that contributed to the structure formation in cooked printed meat analogs. In addition, disulfide bonding was correlated with improved fibrous structures, as observed through SEM.

3D Printing of Textured Soft Hybrid Meat Analogues.

Meat analogue is a food product mainly made of plant proteins. It is considered to be a sustainable food and has gained a lot of interest in recent years. Hybrid meat is a next generation meat analogue prepared by the co-processing of both plant and animal protein ingredients at different ratios and is considered to be nutritionally superior to the currently available plant-only meat analogues. Three-dimensional (3D) printing technology is becoming increasingly popular in food processing. Three-dimensional food printing involves the modification of food structures, which leads to the creation of soft food. Currently, there is no available research on 3D printing of meat analogues. This study was carried out to create plant and animal protein-based formulations for 3D printing of hybrid meat analogues with soft textures. Pea protein isolate (PPI) and chicken mince were selected as the main plant protein and meat sources, respectively, for 3D printing tests. Then, rheology and forward extrusion tests were carried out on these selected samples to obtain a basic understanding of their potential printability. Afterwards, extrusion-based 3D printing was conducted to print a 3D chicken nugget shape. The addition of 20% chicken mince paste to PPI based paste achieved better printability and fibre structure.

Effect of a leucine-enriched essential amino acids mixture on muscle recovery.

[Purpose] The aim of this study was to determine whether the consumption of a leucine-enriched essential amino acid mixture (LEAA), which is known to increase protein synthesis in muscles, alleviates muscle damage and accelerates recovery by ameliorating muscle damage. [Participants and Methods] A double-blind, randomized crossover trial was conducted over a 5-week period. Ten untrained males (age, 23.0 ± 1.6 years) were asked to repeatedly flex and extend their elbows for 10 counts/set × 5 sets at full power while using a dynamometer. The participants took 3.6-g supplements (LEAA mixture or placebo) 3 times daily on day 0 and for the next 7 days. Changes in serum creatine phosphokinase (CPK) activity and myoglobin concentration as markers of muscle tissue damage were evaluated prior to and after exercise and on days 1, 2, 3, 5, and 7. [Results] The relative ratio of the changes in peak serum CPK activity measured on day 5 was significantly lower after taking LEAA than after taking the placebo. [Conclusion] LEAA consumption suppressed exercise-induced elevation of muscle damage markers in blood, which suggests that LEAA could attenuate muscle damage and aid muscle recovery.

The effect of histidine on mental fatigue and cognitive performance in subjects with high fatigue and sleep disruption scores.

Our previous study reported that a dried bonito broth known in Japan as 'dashi' improved or ameliorated mood states, including fatigue, during the daily lives of human subjects. Histidine is an amino acid that is present in dried bonito broth, and we sought to evaluate whether histidine would affect feelings of fatigue in humans. We investigated the effects of histidine intake on the feeling of fatigue, mood states and mental task performance by performing a placebo-controlled, double-blind crossover trial. Twenty subjects with high fatigue and sleep disruption scores were asked to ingest histidine or a placebo every day for two weeks. The subjects' mood states were evaluated using the Profile of Mood States (POMS) scale and a visual analog scale (VAS) for eight feelings (fatigue, depression, carelessness, drowsiness, clear thinking, motivation, attentiveness and concentration). We also measured subjects' cognitive performance using the CogHealth test battery. The fatigue T-scores on the POMS test decreased significantly following histidine ingestion compared to placebo ingestion (p<0.05). After two weeks of histidine ingestion, the reaction time for the working memory task in the CogHealth test battery was significantly shorten compared to placebo ingestion. The VAS scores for clear thinking and for attentiveness were increased significantly following histidine ingestion compared to placebo ingestion (p<0.05). These results suggest that daily ingestion of histidine may ameliorate feelings of fatigue, increase performance during working memory tasks, and improve the clear thinking and attentiveness.

Assessment of the biological similarity of three capsaicin analogs (Capsinoids) found in non-pungent chili pepper (CH-19 Sweet) fruits.

CH-19 Sweet is a newly found chili pepper breed bearing much less pungent fruits. Because CH-19 Sweet fruits were found to contain three analogs (capsinoids) of capsaicin, a major component of pungency of hot peppers (the analogs are capsiate or CST, dihydrocapsiate or DCT, and nordihydrocapsiate or NDCT), we assessed in this study the bio-potencies of these three capsinoids by comparing them with capsaicin. The three capsinoids bound to transient potential vanilloid 1 (TRPV1) receptors expressed in cultured cells and activated Ca(2+) influx in a concentration-dependent manner with similar magnitudes. In contrast to capsaicin, capsinoids at the same concentration induced virtually no nociceptive responses when applied to the eyes or the oral cavities of mice. Intravenous administration of capsaicin or 20-fold increased doses of each capsinoid to rats induced significant increases in plasma catecholamine levels. Orally administered, each capsinoid enhanced oxygen consumption in mice. Based on the present results, capsaicin and these three capsinoids should have similar bio-potency, though capsinoids do not generate pungency or sensory irritation.

Effects of novel capsinoid treatment on fatness and energy metabolism in humans: possible pharmacogenetic implications.

BACKGROUND: Capsinoids from the Capsicum genus of plants are nonpungent capsaicin-related substances with effects on metabolism and body weight in animals. OBJECTIVES: Our objectives were to explore the safety and efficacy of capsinoids taken orally (6 mg/d) for weight loss, fat loss, and change in metabolism and to examine whether candidate genes are predictors of capsinoid response. DESIGN: This was a 12-wk, placebo-controlled, double-blind, randomized study. Eligibility criteria included a body mass index (BMI; in kg/m(2)) of 25-35. Body weight was measured, and dual-energy X-ray absorptiometry, indirect calorimetry (men only), and genotyping were conducted. RESULTS: Forty women and 40 men with a mean (+/- SD) age of 42 +/- 8 y and BMI of 30.4 +/- 2.4 were randomly assigned to a capsinoid or placebo group. Capsinoids were well tolerated. Mean (+/- SD) weight change was 0.9 +/- 3.1 and 0.5 +/- 2.4 kg in the capsinoid and placebo groups, respectively (P = 0.86). There was no significant group difference in total change in adiposity, but abdominal adiposity decreased more (P = 0.049) in the capsinoid group (-1.11 +/- 1.83%) than in the placebo group (-0.18 +/- 1.94%), and this change correlated with the change in body weight (r = 0.46, P < 0.0001). Changes in resting energy expenditure did not differ significantly between groups, but fat oxidation was higher at the end of the study in the capsinoid group (least-squares mean difference: 21.0 mg/min; P = 0.06). Of 13 genetic variants tested, TRPV1 Val585Ile and UCP2 -866 G/A correlated significantly with change in abdominal adiposity. CONCLUSIONS: Treatment with 6 mg/d capsinoids orally appeared to be safe and was associated with abdominal fat loss. Capsinoid ingestion was associated with an increase in fat oxidation that was nearly significant. We identified 2 common genetic variants that may be predictors of therapeutic response.

Characterization of dietary protein-dependent amino acid metabolism by linking free amino acids with transcriptional profiles through analysis of correlation.

This study aims to characterize diet-dependent amino acid metabolism by linking profiles of amino acids concentrations ("aminograms") with transcript datasets through the analysis of correlation. We used a dietary model of protein restriction-to-excess, where rats were fed diets with different levels of casein (5, 10, 15, 20, 30, 50, and 70%) for 2 wk. Twenty-five different amino acids in the plasma, liver, kidney, small intestine, and muscle and 71 gene transcripts in these compartments were measured together with general physiological variables. Under low-protein diet (LPD) conditions, the plasma aminogram for EAA was similar to that of the liver and the small intestine, respectively. Under the high-protein diet (HPD), however, the plasma aminogram for EAA became like that of muscle, while that of NEAA was similar with that of both liver and muscle. To assess the impact of gene expressions in each tissue on the plasma aminograms, correlations were obtained between aminograms and transcripts in each tissue under a diet with different protein levels. Based on the correlations obtained, amino acids and transcripts were systematically connected and then a metabolite-to-gene network was constructed for either LPD or HPD condition. The networks obtained and some other metabolically meaningful relationships such as ureagenesis and serine metabolism clearly illustrated activation of either body protein breakdown with LPD or amino acid catabolism with HPD.

The novel roles of liver for compensation of insulin resistance in human growth hormone transgenic rats.

Chronic excess of GH is known to cause hyperinsulinemia and insulin resistance. We developed human GH transgenic (TG) rats, which were characterized by high plasma levels of human GH and IGF-I. These TG rats showed higher levels of plasma insulin, compared with control littermates, whereas plasma glucose concentrations were normal. Insulin-dependent glucose uptake into adipocytes and muscle was impaired, suggesting that these rats developed insulin resistance. In contrast, insulin-independent glucose uptake into hepatocytes from TG rats was significantly increased, and glycogen and lipid levels in livers of TG rats were remarkably high. Because the role of liver in GH-induced insulin resistance is poorly understood, we studied insulin signaling at early stages and insulin action in liver and primary cultures of hepatocytes prepared from TG rats. There was no difference in insulin receptor kinase activity induced by insulin between TG and control rats; however, insulin-dependent insulin receptor substrate-2 tyrosine phosphorylation, glycogen synthase activation, and expression of enzymes that induce lipid synthesis were potentiated in hepatocytes of TG rats. These results suggest that impairment of insulin-dependent glucose uptake by GH excess in adipose tissue and muscle is compensated by up-regulation of glucose uptake in liver and that potentiation of insulin signaling through insulin receptor substrate-2 in liver experiencing GH excess causes an increase in glycogen and lipid synthesis from incorporated glucose, resulting in accumulation of glycogen and lipids in liver. This novel mechanism explains normalization of plasma glucose levels at least in part in a GH excess model.

Serotonin derivatives, major safflower (Carthamus tinctorius L.) seed antioxidants, inhibit low-density lipoprotein (LDL) oxidation and atherosclerosis in apolipoprotein E-deficient mice.

The effects of defatted safflower seed extract and its phenolic constituents, serotonin derivatives, on atherosclerosis were studied. Ethanol-ethyl acetate extract of safflower seeds (SSE) inhibited low-density lipoprotein (LDL) oxidation induced in vitro by an azo-containing free-radical initiator V70 or copper ions. Two serotonin derivatives [N-(p-coumaroyl)serotonin, CS; N-feruloylserotonin, FS] and their glucosides were identified as the major phenolic constituents of the extract. The study with chemically synthesized materials revealed that a majority of the antioxidative activity of SSE was attributable to the aglycones of these two serotonin derivatives. Orally administered CS and FS suppressed CuSO(4)-induced plasma oxidation ex vivo. Long-term (15 week) dietary supplementation of SSE (1.0 wt %/wt) and synthetic serotonin derivatives (0.2-0.4%) significantly reduced the atherosclerotic lesion area in the aortic sinus of apolipoprotein E-deficient mice (29.2-79.7% reduction). The plasma level of both lipid peroxides and anti-oxidized LDL autoantibody titers decreased concomitantly with the reduction of lesion formation. Serotonin derivatives were detected as both intact and conjugated metabolites in the plasma of C57BL/6J mice fed on 1.0% SSE diet. These findings demonstrate that serotonin derivatives of SSE are absorbed into circulation and attenuate atherosclerotic lesion development possibly because of the inhibition of oxidized LDL formation through their strong antioxidative activity.

Network analysis of plasma and tissue amino acids and the generation of an amino index for potential diagnostic use.

BACKGROUND: Few studies exist on the use of metabolic profiling of amino acids to examine underlying physiologic and disease states. OBJECTIVE: We aimed to introduce a new method for studying relations among amino acids and to generate a diagnostic index, or amino index, based on amino acid concentrations. DESIGN: For network analysis, 35 Fischer-344 rats were randomly divided into 7 groups and fed diets containing 5%, 10%, 15%, 20%, 30%, 50%, or 70% protein. Amino acid concentrations in plasma and various organs were used to derive correlation coefficients that were then used to construct correlation networks. To build a diagnostic index for diabetic rats, the plasma amino acid concentrations of diabetic and normal rats were analyzed by using a novel algorithm developed to generate amino acid-based indexes. Plasma amino acid concentrations from human growth hormone transgenic rats and insulin-treated diabetic rats were used to evaluate the index obtained for diabetes. Dimethylnitrosamine-treated Sprague-Dawley rats were used to generate an index for hepatic fibrosis. RESULTS: The scatter plots of plasma amino acid concentrations showed distinct patterns in different organs that were due to the different protein contents of the diets. Network analysis showed that data-driven networks for blood and tissue could be obtained. We derived a diagnostic index for the discrimination of diabetic rats with both sensitivity and specificity >97% and another surrogate index for liver hydroxyproline with a correlation of r2= 0.85. CONCLUSIONS: Correlation-based network analysis may help to uncover specific physiologic conditions or states. A novel approach using amino acid molar ratios was shown to generate indexes that can be used to separate animal disease models and monitor the progression of a disease parameter. Some of the methods described here may be applicable to the clinical setting.

Effects of pair-feeding and growth hormone treatment on obese transgenic rats.

BACKGROUND: It has been shown that GH-deficient subjects tend to have fat accumulation. We have produced human GH (hGH) transgenic rats that exhibit low circulating hGH levels and hyperphagia. These rats are also characterized by severe obesity, hyperinsulinemia and hyperlipidemia. OBJECTIVE: The present study was conducted in order to elucidate how excess caloric intake and impaired GH secretion account for fat accumulation and metabolic abnormalities in the transgenic rats. DESIGN AND METHODS: The transgenic rats were subjected to either pair-feeding with non-transgenic controls or hGH treatment from 4 to 12 weeks of age, and the effects on fat accumulation and some metabolic parameters were assessed. RESULTS: At the age of 12 weeks, body weight and food intake were greater in transgenic than in control rats by 10% and 27% respectively. The ratio of epididymal white adipose tissue weight to body weight (WAT/BW) was more than three times greater in transgenic than in control rats. Although pair-feeding for 8 weeks decreased body weight, it did not affect the WAT/BW ratio. Treatment with hGH affected neither body weight nor food intake, while it reduced the WAT/BW ratio by 30%. Serum concentrations of triglyceride, free fatty acid, insulin and leptin were all significantly higher in the transgenic than in the control rats. Pair-feeding decreased serum triglyceride, insulin and leptin levels, but not serum free fatty acid levels. On the other hand, hGH treatment decreased only serum leptin concentrations. CONCLUSIONS: These results suggest that severe fat accumulation in the transgenic rats mainly resulted from the decreased lipolytic action of GH, while metabolic abnormalities mainly resulted from excess caloric intake.

Effects of pulsatile secretion of growth hormone (GH) on fat deposition in human GH transgenic rats.

Growth hormone (GH) is an endocrine regulator of glucose and lipid metabolism as well as body growth. GH levels are decreased and a unique pulsatile secretory pattern becomes obvious after puberty particularly in males. Coincidentally with this, males tend to deposit body fat. Experimental and clinical evidence has accumulated that obesity is associated with a decrease in GH levels. A strain of transgenic rats has been generated with severe obesity but normal nose-to-tail length, which has low circulating GH levels without pulsatility (human growth hormone (hGH) transgenic rats). The present review mainly focuses on recent and current work analysing the relationship between the occurrence of obesity and low GH levels and/or the absence of GH pulsatility in this transgenic animal model. This model has elevated blood glucose, non-esterified fatty acid, insulin and leptin levels associated with hyperphagia, suggesting that these rats also carry insulin- and leptin-resistant characteristics. hGH transgenic rats were subjected to a pair-feeding treatment to normalize food intake and chronic GH replacement to normalize GH levels. While the pair-feeding for 8 weeks successfully suppressed body-weight gain, the fat pad : body weight ratio remained very similar to freely-eating control hGH transgenic rats, which indicates the hyperphagia is not the sole contributor to the excess fat accumulation in this model. However, continuous elevation of peripheral hGH levels (approximately 2-fold) for 8 weeks by means of a slow-release vehicle resulted in a significant decrease in the fat mass : body weight ratios by 30 %. This GH treatment altered neither food intake nor body-weight gain. Thus, two characteristic phenotypes observed in the hGH transgenic rats, hyperphagia and obesity, seem to be closely related to GH levels and GH secretory pattern. This relationship might be working in the regulation of changes in seasonal body composition in wild animals.