A study on the protein fraction of coffee silverskin: Protein/non-protein nitrogen and free and total amino acid profiles

Machado, Susana; Costa, Anabela S.G.; B., Filipa Pimentel; Oliveira, M. Beatriz P.P.; Alves, Rita C.

doi:10.1016/j.foodchem.2020.126940

Cited by 35 publications

(26 citation statements)

References 17 publications

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“…Based on the results of this study, the consumption of a 5 g portion (ds) of Porphyra dioica conchocelis, Porphyra umbilicalis conchocelis, Porphyra dioica blades, Porphyra umbilicalis blades, Gracilaria vermiculophylla , and Ulva rigida provides an average of 1.43, 1.15, 1.02, 0,97, 0.53, and 0.48 g of protein, respectively. Considering that the RDA of protein intake for an adult of 70 kg is equivalent to 58 g [ 25 ] the intake of 5 g (ds) of the Porphyra dioica conchocelis, Porphyra umbilicalis conchocelis, Porphyra dioica blades, Porphyra umbilicalis blades, Gracilaria vermiculophylla , and Ulva rigida contributes to 2.47, 1.99, 1.76, 1.67, 0.92, and 0.83% of RDA, respectively. Based on these observations, seaweeds can be a sustainable alternative to diversify or complement the diet.…”

Section: Resultsmentioning

confidence: 99%

“…The total amino acids were determined according to the protocol described by Machado et al [ 25 ] with minor modifications. Briefly, 150 mg of sample were weighed and mixed with 3 mL of 6 M HCl in a screw-cap tube.…”

Section: Methodsmentioning

confidence: 99%

“…The extraction of free amino acids was based on the study by Machado et al [ 25 ]. Briefly, samples were prepared by dispersing the milled sample in deionized water (1:25, w/v ).…”

Section: Methodsmentioning

confidence: 99%

“…The total and free amino acids contents were analyzed by RP-HPLC (Reverse Phase-High Performance Liquid Chromatography) using an integrated system from Jasco (Jasco, Japan) equipped with two high-pressure pumps (PU-980), an automatic injector (AS-4150), a fluorescence detector (FP-2020 Plus), and a UV/Vis absorption detector (MD-2015 Plus). The samples (extracts of total and free amino acids) were derivatized online with OPA/3-MPA and FMOC as described by Machado et al [ 25 ]. Amino acids were identified based on the retention time of the corresponding standards.…”

Section: Methodsmentioning

confidence: 99%

“…Total nitrogen (TN) was estimated by Kjeldahl analysis (AOAC, method 984.13) [ 28 ]. Protein nitrogen (PN) was determined as described by Machado et al [ 25 ]. Each sample was precipitated with 15% ( w/v ) trichloroacetic acid prior filtering the solution using a low N content filter paper (GPL, Porto, Portugal).…”

Section: Methodsmentioning

confidence: 99%

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Amino Acid Profile and Protein Quality Assessment of Macroalgae Produced in an Integrated Multi-Trophic Aquaculture System

Machado

Pimentel

et al. 2020

Foods

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Seaweeds are a recognized source of bioactive compounds and techno-functional ingredients. However, its protein fraction is still underexplored. The aim of this study was to determine the total and free amino acid profile and protein content of four seaweeds species (Porphyra dioica, Porphyra umbilicalis,Gracilaria vermiculophylla, and Ulva rigida) produced in an integrated multi-trophic aquaculture system, while assessing their protein quality. Samples were submitted to acid and alkaline hydrolysis (total amino acids) and to an aqueous extraction (free amino acids) followed by an automated online derivatization procedure, and analyzed by reverse phase-high performance liquid chromatography. Protein-, non-protein and total-nitrogen were quantified by the Kjeldahl method. Crude and true protein contents were estimated based on the nitrogen and amino acid composition. Protein quality was assessed based on the amino acids profile. Porphyra species presented the highest protein content compared to the remaining three seaweed species tested. All samples presented a complete profile of essential amino acids and a high quality protein profile, according to World Health Organization and Food and Agriculture Organization standards. Methionine and tryptophan were the first limiting amino acids in all species. Red species (Porphyra and Gracilaria) presented high levels of free alanine, glutamic, and aspartic acids. The results highlight the potential of using seaweeds as an alternative and sustainable source of protein and amino acids for human nutrition and industrial food processing.

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Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

“…The extraction of free amino acids was based on the study by Machado et al [ 25 ]. Briefly, samples were prepared by dispersing the milled sample in deionized water (1:25, w/v ).…”

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

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Amino Acid Profile and Protein Quality Assessment of Macroalgae Produced in an Integrated Multi-Trophic Aquaculture System

Machado

Pimentel

et al. 2020

Foods

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Coffee Proteins

Iriondo‐DeHond

Salazar

Domènech

et al. 2022

Molecular Mechanisms of Functional Food

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Effects of different protease treatment on protein degradation and flavor components of Lentinus edodes

Fang

Chen

et al. 2022

eFood

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Shiitake mushrooms (Lentinus edodes) form a great source of protein; however, the effect of enzymatic hydrolysis to improve its flavor has not yet been investigated. To explore the effects of different protease treatments on protein degradation and flavor compounds of shiitake mushrooms, papain, neutral protease, and flavourzyme were selected for the hydrolysis of shiitake mushrooms. Proteolysis index, Trichloroacetic acid-nitrogen soluble index, and protein content were estimated to evaluate protein degradation. Flavor amino acids and volatile components of the hydrolysate were also analyzed. Results showed flavourzyme has an advantage over the others in promoting protein degradation and improving flavor. Compared to single-enzyme treatment, a combination treatment with three enzymes, at 1:1:1 ratio, was found to perform greater protein hydrolysis. After protease-mediated hydrolysis, the variety and content of flavor substances (free amino acids and eight-carbon compounds) in L. edodes increased. We concluded that protease treatment is an effective method for improving the quality and flavor of L. edodes.

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A study on the protein fraction of coffee silverskin: Protein/non-protein nitrogen and free and total amino acid profiles

Cited by 35 publications

References 17 publications

Amino Acid Profile and Protein Quality Assessment of Macroalgae Produced in an Integrated Multi-Trophic Aquaculture System

Amino Acid Profile and Protein Quality Assessment of Macroalgae Produced in an Integrated Multi-Trophic Aquaculture System

Coffee Proteins

Effects of different protease treatment on protein degradation and flavor components of Lentinus edodes

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