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INTRODUCTION: Plant-derived proteins have received considerable attention as an alternative to animal based proteins and are now frequently used in both plant-based diets and sports nutrition products. However, little information is available on the anabolic properties of potato-derived protein. This study compares muscle protein synthesis rates following the ingestion of 30 g potato protein versus 30 g milk protein at rest and during recovery from a single bout of resistance exercise in healthy, young males.METHODS: In a randomized, double blind, parallel-group design, 24 healthy young males (24 ± 4y) received primed continuous L-[ring-13C6]-phenylalanine infusions while ingesting 30 g potato derived protein or 30 g milk protein following a single bout of unilateral resistance exercise. Blood and muscle biopsies were collected for 5 hours following protein ingestion to assess post-prandial plasma amino acid profiles and mixed muscle protein synthesis rates at rest and during recovery from exercise.RESULTS: Ingestion of both potato and milk protein increased mixed muscle protein synthesis rates when compared to basal post-absorptive values (from 0.020 ± 0.011 to 0.053 ± 0.017 %·h-1 and from 0.021 ± 0.014 to 0.050 ± 0.012 %·h-1, respectively (P < 0.001)), with no differences between treatments (P = 0.54). In the exercised leg, mixed muscle protein synthesis rates increased to 0.069 ± 0.019 and 0.064 ± 0.015 %·h-1 after ingesting potato and milk protein, respectively (P < 0.001), with no differences between treatments (P = 0.52). The muscle protein synthetic response was greater in the exercised compared with the resting leg (P < 0.05).CONCLUSIONS: Ingestion of 30 g potato protein concentrate increases muscle protein synthesis rates at rest and during recovery from exercise in healthy, young males. Muscle protein synthesis rates following the ingestion of 30 g potato protein do not differ from rates observed after ingesting an equivale

Physical activity increases muscle protein synthesis rates. However, the impact of exercise on the coordinated up- and/or downregulation of individual protein synthesis rates in skeletal muscle tissue remains unclear. The authors assessed the impact of exercise on mixed muscle, myofibrillar, and mitochondrial protein synthesis rates as well as individual protein synthesis rates in vivo in rats. Adult Lewis rats either remained sedentary (n = 3) or had access to a running wheel (n = 3) for the last 2 weeks of a 3-week experimental period. Deuterated water was injected and subsequently administered in drinking water over the experimental period. Blood and soleus muscle were collected and used to assess bulk mixed muscle, myofibrillar, and mitochondria' protein synthesis rates using gas chromatography-mass spectrometry and individual muscle protein synthesis rates using liquid chromatography-mass spectrometry (i.e., dynamic proteomic profiling). Wheel running resulted in greater myofibrillar (3.94 +/- 0.26 vs. 3.03 +/- 0.15%/day; p<.01) and mitochondria' (4.64 +/- 0.24 vs. 3.97 +/- 0.26%/day; p <.05), but not mixed muscle (2.64 +/- 0.96 vs. 2.38 +/- 0.62%/day; p = .71) protein synthesis rates, when compared with the sedentary condition. Exercise impacted the synthesis rates of 80 proteins, with the difference from the sedentary condition ranging between -64% and +420%. Significantly greater synthesis rates were detected for F1-ATP synthase, ATP synthase subunit alpha, hemoglobin, myosin light chain-6, and synaptopodin-2 (p <.05). The skeletal muscle protein adaptive response to endurance-type exercise involves upregulation of mitochondria' protein synthesis rates, but it is highly coordinated as reflected by the up-and downregulation of various individual proteins across different bulk subcellular protein fractions.

Physical activity increases muscle protein synthesis rates. However, the impact of exercise on the coordinated up- and/or downregulation of individual protein synthesis rates in skeletal muscle tissue remains unclear. The authors assessed the impact of exercise on mixed muscle, myofibrillar, and mitochondrial protein synthesis rates as well as individual protein synthesis rates in vivo in rats. Adult Lewis rats either remained sedentary (n = 3) or had access to a running wheel (n = 3) for the last 2 weeks of a 3-week experimental period. Deuterated water was injected and subsequently administered in drinking water over the experimental period. Blood and soleus muscle were collected and used to assess bulk mixed muscle, myofibrillar, and mitochondria' protein synthesis rates using gas chromatography-mass spectrometry and individual muscle protein synthesis rates using liquid chromatography-mass spectrometry (i.e., dynamic proteomic profiling). Wheel running resulted in greater myofibrillar (3.94 +/- 0.26 vs. 3.03 +/- 0.15%/day; p<.01) and mitochondria' (4.64 +/- 0.24 vs. 3.97 +/- 0.26%/day; p <.05), but not mixed muscle (2.64 +/- 0.96 vs. 2.38 +/- 0.62%/day; p = .71) protein synthesis rates, when compared with the sedentary condition. Exercise impacted the synthesis rates of 80 proteins, with the difference from the sedentary condition ranging between -64% and +420%. Significantly greater synthesis rates were detected for F1-ATP synthase, ATP synthase subunit alpha, hemoglobin, myosin light chain-6, and synaptopodin-2 (p <.05). The skeletal muscle protein adaptive response to endurance-type exercise involves upregulation of mitochondria' protein synthesis rates, but it is highly coordinated as reflected by the up-and downregulation of various individual proteins across different bulk subcellular protein fractions.

The anabolic action of "fast" whey protein on the regulation of postprandial muscle protein synthesis has been established to be short-lived in healthy young adults. We assessed the time course of anabolic signaling activation and stimulation of myofibrillar protein synthesis rates (MPS) after ingestion of a food source that represents a more typical meal-induced pattern of aminoacidemia. Seven young men (age: 22 +/- 1 y) underwent repeated blood and biopsy sampling during primed, continuous L-[ring(2)H(5)]phenylalanine and L-[1-C-13]leucine tracer infusions and ingested 38 g of L-[1-C-13]phenylalanine- and L-[1-C-13]leucine-labeled milk protein concentrate. A total of similar to 27 +/- 4 (similar to 10 g) and similar to 31 +/- 1% (similar to 12 g) of dietary protein-derived amino acids were released in circulation between 0 and 120 min and 120-300 min, respectively, of the postprandial period. L-[ring-H-2(5)]phenylalanine-based MPS increased above basal (0.025 +/- 0.008%/h) by similar to 75% (0.043 +/- 0.009%/h; P = 0.05) between 0 and 120 min and by similar to 86% (0.046 +/- 0.004%/h; P = 0.02) between 120 and 300 min, respectively. L-[1-C-13]leucine-based MPS increased above basal (0.027 +/- 0.002%/h) by similar to 72% (0.051 +/- 0.016%/h; P = 0.10) between 0 and 120 min and by similar to 62% (0.047 +/- 0.004%/h; P = 0.001) between 120 and 300 min, respectively. Myofibrillar protein-bound L-[1-C-13]phenylalanine increased over time (P <0.001) and equaled 0.004 +/- 0.001, 0.008 +/- 0.002, 0.017 +/- 0.004, and 0.020 +/- 0.003 mole percent excess at 60, 120, 180, and 300 min, respectively, of the postprandial period. Milk protein ingestion increased mTORC1 phosphorylation at 120, 180, and 300 min of the postprandial period (all P <0.05). Our results show that ingestion of 38 g of milk protein results in sustained increases in MPS throughout a 5-h postprandial period in healthy young men.NEW & NOTEWORTHY The stimulation of muscle protein synthesis

The anabolic action of "fast" whey protein on the regulation of postprandial muscle protein synthesis has been established to be short-lived in healthy young adults. We assessed the time course of anabolic signaling activation and stimulation of myofibrillar protein synthesis rates (MPS) after ingestion of a food source that represents a more typical meal-induced pattern of aminoacidemia. Seven young men (age: 22 +/- 1 y) underwent repeated blood and biopsy sampling during primed, continuous L-[ring(2)H(5)]phenylalanine and L-[1-C-13]leucine tracer infusions and ingested 38 g of L-[1-C-13]phenylalanine- and L-[1-C-13]leucine-labeled milk protein concentrate. A total of similar to 27 +/- 4 (similar to 10 g) and similar to 31 +/- 1% (similar to 12 g) of dietary protein-derived amino acids were released in circulation between 0 and 120 min and 120-300 min, respectively, of the postprandial period. L-[ring-H-2(5)]phenylalanine-based MPS increased above basal (0.025 +/- 0.008%/h) by similar to 75% (0.043 +/- 0.009%/h; P = 0.05) between 0 and 120 min and by similar to 86% (0.046 +/- 0.004%/h; P = 0.02) between 120 and 300 min, respectively. L-[1-C-13]leucine-based MPS increased above basal (0.027 +/- 0.002%/h) by similar to 72% (0.051 +/- 0.016%/h; P = 0.10) between 0 and 120 min and by similar to 62% (0.047 +/- 0.004%/h; P = 0.001) between 120 and 300 min, respectively. Myofibrillar protein-bound L-[1-C-13]phenylalanine increased over time (P <0.001) and equaled 0.004 +/- 0.001, 0.008 +/- 0.002, 0.017 +/- 0.004, and 0.020 +/- 0.003 mole percent excess at 60, 120, 180, and 300 min, respectively, of the postprandial period. Milk protein ingestion increased mTORC1 phosphorylation at 120, 180, and 300 min of the postprandial period (all P <0.05). Our results show that ingestion of 38 g of milk protein results in sustained increases in MPS throughout a 5-h postprandial period in healthy young men.NEW & NOTEWORTHY The stimulation of muscle protein synthesis

Resistance-type exercise increases muscle protein synthesis rates during acute postexercise recovery. The impact of resistance-type exercise training on (local) muscle protein synthesis rates under free-living conditions on a day-to-day basis remains unclear. We determined the impact of daily unilateral resistance-type exercise on local myofibrillar protein synthesis rates during a 3-day period. Twelve healthy young men (22 +/- 1 yr) were recruited to participate in this study where they performed daily, unilateral resistance-type exercise during a 3-day intervention period. Two days before the exercise training subjects ingested 400 ml deuterated water (2H(2)O). Additional 50-ml doses of deuterated water were ingested daily during the training period. Saliva and blood samples were collected daily to assess body water and amino acid precursor deuterium enrichments, respectively. Muscle tissue biopsies were collected before and after the 3 days of unilateral resistance-type exercise training from both the exercised and the nonexercised, control leg for the assessment of muscle protein synthesis rates. Deuterated water dosing resulted in a steady-state body water enrichment of 0.70 +/- 0.03%. Intramuscular free [2H] alanine enrichment increased up to 1.84 +/- 0.06 mole percent excess (MPE) before the exercise training and did not change in both the exercised and control leg during the 3 subsequent exercise training days (2.11 +/- 0.11 and 2.19 +/- 0.12 MPE, respectively; P > 0.05). Muscle protein synthesis rates averaged 1.984 +/- 0.118 and 1.642 +/- 0.089%/day in the exercised vs. nonexercised, control leg when assessed over the entire 3-day period (P < 0.05). Daily resistance-type exercise stimulates (local) muscle protein synthesis in vivo in humans. NEW & NOTEWORTHY This study demonstrates that daily resistance-type exercise stimulates muscle protein synthesis rates in vivo in humans over multiple days. Whereas acute studies have shown that resistance-ty

Resistance-type exercise increases muscle protein synthesis rates during acute postexercise recovery. The impact of resistance-type exercise training on (local) muscle protein synthesis rates under free-living conditions on a day-to-day basis remains unclear. We determined the impact of daily unilateral resistance-type exercise on local myofibrillar protein synthesis rates during a 3-day period. Twelve healthy young men (22 +/- 1 yr) were recruited to participate in this study where they performed daily, unilateral resistance-type exercise during a 3-day intervention period. Two days before the exercise training subjects ingested 400 ml deuterated water (2H(2)O). Additional 50-ml doses of deuterated water were ingested daily during the training period. Saliva and blood samples were collected daily to assess body water and amino acid precursor deuterium enrichments, respectively. Muscle tissue biopsies were collected before and after the 3 days of unilateral resistance-type exercise training from both the exercised and the nonexercised, control leg for the assessment of muscle protein synthesis rates. Deuterated water dosing resulted in a steady-state body water enrichment of 0.70 +/- 0.03%. Intramuscular free [2H] alanine enrichment increased up to 1.84 +/- 0.06 mole percent excess (MPE) before the exercise training and did not change in both the exercised and control leg during the 3 subsequent exercise training days (2.11 +/- 0.11 and 2.19 +/- 0.12 MPE, respectively; P > 0.05). Muscle protein synthesis rates averaged 1.984 +/- 0.118 and 1.642 +/- 0.089%/day in the exercised vs. nonexercised, control leg when assessed over the entire 3-day period (P < 0.05). Daily resistance-type exercise stimulates (local) muscle protein synthesis in vivo in humans. NEW & NOTEWORTHY This study demonstrates that daily resistance-type exercise stimulates muscle protein synthesis rates in vivo in humans over multiple days. Whereas acute studies have shown that resistance-ty

Properties and storage stability of two different jumbo squid myofibrillar protein-based films were investigated. Myofibrillar proteins were extracted by isoelectric precipitation after acidic and alkaline solubilization, obtaining the same extraction yield. During extraction the edible fraction, which was discarded during mantle skinning, was recovered, and the fishy flavour produced by nitrogen and other undesirable compounds was removed, although some sarcoplasmic proteins were lost simultaneously. In alkaline-Concentrate (C), myosin unfolding led to water resistant films, less water vapour permeable and more mechanically resistant than acidic-Films (F); whereas acidic-C protein hydrolysis resulted in more transparent and soluble films, with higher protein release (~80g/L). During 4 months of storage some structure reorganization occurred, and both films incremented their yellowish tendency, especially the acidic-F, being this attributed to a Maillard reaction with plasticizers. After storage time, water solubility increased in C-films. While acidic-F aggregation led to a protein release reduction and tensile strength improvement, alkali-F became weak and brittle, loosing transparency. C-films offered different filmogenic properties, proving to be promising biodegradable packaging materials. © 2013 Elsevier Ltd.