Chemical composition and in vitro antioxidant property of peptides produced from cottonseed meal by solid-state fermentation

Figures & data

Table 1. Average yield and proximate composition of cottonseed meal (CSM) and cottonseed peptides (CPs).

Tabla 1. Rendimiento promedio y composición proximal de la harina de semilla de algodón (CSM) y de los péptidos de semilla de algodón (CPs).

Parameters	Meal	CP
Yield (%)^1	ND^2	19.2 ± 1.09^3
Protein (g kg^−1)	468.6 ± 7.07	879.9 ± 13.40
Fat (g kg^−1)	14.9 ± 0.07	0.74 ± 0.03
Fiber (g kg^−1)	101.2 ± 8.89	31.1 ± 0.07
Ash (g kg^−1)	54.9 ± 0.87	21.0 ± 0.21
Total phenolics^4)	1.34 ± 0.08	0.28 ± 0.02
Free gossypol (mg kg^−1)	745 ± 0.06	ND

Notes: ¹Protein yield was calculated as the protein percentage of CP related to the initial protein content of meal sample.²ND: not detected.³Values are expressed as the mean ± SD from triplicate measurements.⁴The total phenolic content was expressed as milligram gallic acid equivalents per gram of crude extract.

Figure 1. 1,1-diphenyl-2-picrylhydrazyl radical-scavenging activity of cottonseed peptides (CPs). Each value is expressed as mean ± SD (n = 3). Butylated hydroxytoluene (BHT) was used as a positive control.

Figura 1. Actividad de los péptidos de semilla de algodón (CP) en la eliminación del radical 1,1-difenil-2-picrilhidrazyl. Cada valor se expresa como una media ± DE (n = 3). Se utilizó butilhidroxitolueno (BHT) como control positivo.

Figure 2. Hydroxyl radical-scavenging activities of cottonseed peptides (CPs). Each value is expressed as mean ± SD (n = 3). Butylated hydroxytoluene (BHT) was used as a positive control.

Figura 2. Actividades de los péptidos de semilla de algodón (CPs) en la eliminación del radical hidroxilo. Cada valor se expresa como una media ± DE (n = 3). Se utilizó butilhidroxitolueno (BHT) como control positivo.

Figure 3. Metal-chelating activity of cottonseed peptides (CPs). Each value is expressed as mean ± SD (n = 3). Ethylene diamine tetraacetic acid (EDTA) was used as a positive control.

Figura 3. Actividad quelante de metales de los péptidos de semilla de algodón (CPs). Cada valor se expresa como media ± DE (n = 3). Se utilizó el ácido etilendiaminotetraacético (EDTA) como control positivo.

Figure 4. Reducing power of cottonseed peptides (CPs). Each value is expressed as mean ± SD (n = 3). Ascorbic acid (Vc) was used as a positive control.

Figura 4. Poder reductor de los péptidos de semilla de algodón (CPs). Cada valor se expresa como una media ± DE (n = 3). Se utilizó el ácido ascórbico (Vc) como control positivo.

Figure 5. Cytotoxicity of cottonseed peptides (CPs) (A) and its protective effects against H₂O₂-induced decrease of Raw 264.7 cell viability (B). Each value is expressed as mean ± SD (n = 3). Bars with different alphabets have significantly different mean values at P < 0.05. Cells treated with complete medium only were used as a positive control (C). Cells treated with H₂O₂ only were used as a negative control (H₂O₂).

Figura 5. Citotoxicidad de los péptidos de semilla de algodón (CPs) (A) y sus efectos protectores contra la reducción de la viabilidad de células Raw 264,7 inducida por H₂O₂ (B). Cada valor se expresa como una media ± DE (n = 3). Las barras con letras diferentes tienen valor medio significativamente diferente en P < 0,05. Las células tratadas solo con un medio completo fueron utilizadas como un control positivo (C). Las células tratadas solo con H₂O₂ fueron utilizadas como un control negativo (H₂O₂).

Table 2. Total amino acid composition of cottonseed peptides (g kg^–1 dry weight of extract sample).

Tabla 2. Composición de los aminoácidos totales de los péptidos de semilla de algodón (g kg⁻¹ peso seco de la muestra extraída).

Amino acids	Content	FAO/WHO (2007)
Aspartic acid	81.4^1
Threonine	30.1	23.0
Serine	43.0
Glutamic acid	211.7
Proline	39.8
Glycine	38.6
Alanine	36.9
Valine	39.2	39.0
Methionine	9.0
Isoleucine	29.5	30.0
Leucine	54.8	59.0
Tyrosine	21.7
Phenylalanine	52.2
Phenylalanine + Tyrosine	73.9	38.0
Histidine	32.1	15.0
Lysine	36.6	45.0
Arginine	97.5
Tryptophan	ND^2	6.0
AAA^3	293.1
BAA^4	166.2
HAA^5	283.1
Total amino acids	854.1

Notes: ¹Values are expressed as the mean from triplicate measurements.²ND: not determined.³Acidic amino acids (AAA): aspartic acid and glutamic acid.⁴Basic amino acids (BAA): arginine, histidine, and lysine.⁵Hydrophobic amino acids (HAA): valine, leucine, proline, methionine, phenylalanine, and isoleucine.

Table 3. Molecular weight distribution of cottonseed peptides.

Tabla 3. Distribución del peso molecular de los péptidos de semilla de algodón.

Molecular weight (Da)^1	Distribution (%)
3000–1000	43.48
1000–600	18.06
600–400	22.29
400–158	10.84
<158	5.33

Note: ¹The molecular weights for all samples were calculated according to the standard equation as follows: retention time = –5.1737 × Log (molecular weight) + 34.493 (R² = 0.973), using gel permeation chromatography option of Waters Empower 2 software.

FAO. (2007). Protein and amino acid requirements in human nutrition (WHO technical report series, No. 935). Geneva, Switzerland: World Health Organization (WHO) Press. Retrieved from whqlibdoc.who.int/trs/who_trs_935_eng.pdf

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