Dužina kokosového ořechu

Coconut meat

Produkty z dužiny

• Fleshy part of the seed
• Fresh or dried in cooking
• Coconut cream and coconut milk
• Made by pressing the flesh to extract fluid
• These are used in many countries in cooking
• Coconut milk is a component of many curries in India, Sri Lanka and other Asian countries
• Desiccated coconut
• Coconut flour
• Coconut chips and flakes [9]

Obecné vlastnosti

• Each of these products has a lipid (MCFA) component
• May also contain high levels of both soluble and insoluble fibre
• Varying levels of the antioxidants and other beneficial components [9]

Lipidogram

• Many of these coconut products can improve lipid profiles and other benefits [9]

Diabetes

• Salil et al.:
• Improvement in diabetic indicators following the consumption of coconut flesh
• Believed to be due to the protein content of coconut [9]

Nuciferoic Acid

• A Novel Keto Fatty Acid with Hyaluronidase Inhibitory Activity from Cocos nucifera Linn. Endocarp.
• Spectral characterization of the molecule indicated that it is a novel keto fatty acid
• Hyaluronidase inhibitory potential of the nuciferoic acid was found to be moderate [33]
• It was further docked in all the ten cavities of hyaluronidase
• Cavity 1 and cavity 4 could be the probable sites of action on hyaluronidase for nuciferoic acid [33]
• Key sites of metabolism on nuciferoic acid are C1, C2, C14 and C17
• Toxicity prediction against 55 toxicological endpoints revealed no indication of existing toxicological features [33]
• PMID: 30582479 DOI: 10.2174/1568026619666181224111319 [33]

Coconut flakes

• Have been shown to
• Reduce total cholesterol as well as LDL-C and serum TAG levels [9]

Coconut kernel

• protein rich in arginine
• Observed anti-diabetic activity of coconut flesh
• Suggested to be due to the arginine,
• Influence pancreatic b cell regeneration [9]

[30]

Proteiny kokosu - dřeně

Isolation and fractionation

• Several procedures developed
• Isoelectric (pI) precipitation
• Heat coagulation
• Combined isoelectric precipitation as well as heat coagulation
• Co-precipitation with a calcium salt [30]
• High yield of protein was achieved by
• Heat coagulation
• Followed by pI precipitation [30]
• Capulso et al. (1981) studied the effect of heat coagulation, isoelectric precipitation and simultaneous pH and heat coagulation on the recovery of coconut proteins from skim milk
• 84% of proteins in the skim milk
• Were precipitated with HCl at pH 4
• Further coagulated by heat at 90 °C for 30 min [30]
• Proteins were extracted using alkaline extraction process from coconut milk press cake
• Using saturated Na3PO4
• Yield of 47% was obtained (Chambal, Bergenstahl, & Dejmek, 2012) [30]

Klaisfikace dle extrakčních metod

• Generally classified according to their solubility and amino acid composition (Rasyid et al., 1992)
• Can be fractionated into five fractions using different solvents
• Water,
• Sodium chloride,
• Isopropanol,
• Acetic acid,
• Sodium hydroxide soluble fractions [30]

Skupiny proteinů kokosvé dužiny

• Are designated as:
• Albumin,
• Globulin,
• Prolamin,
• Glutelin-1,
• Glutelin-2 fractions [30]

• The predominant proteins in coconut endosperm or kernel
• Globulin (salt-soluble) 40% of total protein
• Albumin (water-soluble) 21% of total protein (Balachandran, Arumughan, & Mathew, 1985; Kwon et al., 1996) [30]
• Relative proportion of each protein fraction affects the functional properties and the nutritional quality
• The differences in maturation stage, fertilizer, climate, starting material, and so on, also result in varying proportion of various proteins in coconut meat (Patil & Benjakul, 2017) [30]

Globulin fraction of coconut

• High level of charged amino acids
• Aspartic acid,
• Glutamic acid,
• Arginine,
• lysine (Kwon et al., 1996; Patil & Benjakul, 2017) [30]
• Two major types of globulin fractions:
• 11S globulin
• Cocosin
• One of seed storage proteins
• 86% of the total globulin (Balasundaresan, Sugadev, & Ponnuswamy, 2002) [30]
• 7S globulin

Albumin fraction

• Has higher proportions of amino acids with polar side chains [30]

Molecular weight

• Albumin fraction MW
• From 18 to 52 kDa
• Globulin fraction
• Below 60 kDa
• Cocosin
• Major protein (65%)
• MW of 55 kDa
• Observed in the endosperm of coconut (Garcia et al., 2005) [30]
• Prolamin fraction
• 17 to 56 kDa
• Glutelin-1 fraction
• 14 to 100 kDa [30]

Cocosin

• Generally hexameric quaternary in structure
• MW is about 300 to 360 kDa
• Each subunit has MW of 55 kDa
• Basic (22 to 24 kDa)
• Acidic (32 to 34 kDa) polypeptides
• Linked via disulfide bridge
• Chains are dissociated under the reducing conditions (Garcia et al., 2005) [30]

7S coconut globulin

• Type of vicilins
• Trimer
• Oligomeric MW of 150 to 190 kDa
• Each single chain subunit of about 55 kDa (Garcia et al., 2005)
• Coconut 7S globulin is unglycosylated
• Lack of sulfur-containing amino acids (Carr, Plumb, Parker, & Lambert, 1990) [30]

Amino acid compositions

• Coconut proteins generally provide good nutritional value with a relatively balanced amino acid profile (Gonzales & Tanchuco, 1977; Gunetileke & Laurentius, 1974; Kwon et al., 1996; Rasyid et al., 1992) [30]
• Contain a high amount of essential amino acids (71% to 77%) [30]
• Digestibility of 86% to 94% (Hagenmaier, Mattil, & Cater, 1974; Molina & Lachance, 1973) [30]

• Coconut proteins have comparatively
• High level of
• Glutamic acid (17.0% to 27.2%)
• Arginine (14.2% to 17.9%)
• Aspartic acid (5.6% to 8.9%)
• Are deficient in
• methionine (1.2% to 2.9%; Kwon et al., 1996) [30]

Albumin fractions

• Most amino acid levels are lower in the albumin fraction
• Except glutamic acid, arginine, and lysine
• Which are higher than those found in glutelin-1 and globulin fractions [30]

Globulin fractions

• The coconut globulin contains
• High amount of essential amino acids including
• valine
• phenylalanine [30]
• Has less
• Glutamic acid,
• lysine,
• Arginine than the albumin (Kwon et al., 1996) [30]

• The leucine and phenylalanine of globulin fraction
• Comparable to those guided by FAO
• Globulin and glutelin-1 fractions
• Show higher valine content [30]
• Threonine, cysteine, and methionine
• Seemed to be the limiting amino acids for coconut proteins (Kwon et al., 1996)

[30]

Doporučené dávky AMK dle FAO pro srovnání

[31]

Funkční vlastnosti proteinů kokosové dužiny

• Depend strongly on their solubility
• Generally low between pH 4 and 5
• Increased when pHs are above or below such pHs [30]
• proteins of coconut endosperm from different regions have different solubility (Balachandran et al., 1985)
• Associated with different amino acid profiles [30]
• Minimum solubility of major protein components of coconut protein isolate, coconut skim milk, and the extracts of coconut endosperm
• Observed between pH 4 and 5
• Range of isoelectric point of those proteins (Balasubramaniam & Sihotang, 1979; Gonzales & Tanchuco, 1977; Hagenmaier et al., 1974; Kwon & Rhee, 1996) [30]
• Maximum solubility
• Reported at pH 10.3 (Balasubramaniam & Sihotang, 1979) [30]
• Foaming capacity of coconut protein isolate
• Also affected by pH
• At pH 2 and 11, foam expansion was highest
• Foam stability was low (Gonzales & Tanchuco, 1977) [30]
• Profound role in emulsion stability
• proteins isolated from coconut skim milk effectively stabilized emulsions that are fairly viscous
• Ionic strength, pH, and especially temperature
• Drastically influence emulsifying properties of coconut proteins (Kwon & Rhee, 1996; Onsaard et al., 2006) [30]
• Proteins form a protective barrier film around oil droplets
• Repulsion (e.g., electrostatic and steric) between the oil droplets prevent their coalescence
• Effects of sonication (120 W, 20 kHz and 250 W, 20 kHz)
• On the stability of sunflower oil-in-water emulsions prepared by coconut milk protein was studied (Lad and Murthy; 2012)
• Was very stable [30]
• Solubility and emulsification properties of a crude freeze-dried alkaline protein extract (APE)
• Increased at pH above and below 3 to 4 [30]
• protein concentrate from a by-product of coconut processing
• Protein powders from milk cake
• Higher oil and water absorption capacities [30]
• protein powders from oil cake
• Better emulsifying and foaming properties [30]
• Globulin fraction was more competent as an emulsifier in the oil-in-water emulsion as compared to albumin
• Possibly related to varying amino acid compositions
• Proportion of nonpolar and polar amino acids, mainly on the surface of the protein, determine emulsifying property
• Hydrophobic proteins with nonpolar side chains exhibits high emulsifying properties (Patil & Benjakul, 2017) [30]

Thermal property

• Coconut proteins have been shown to be highly sensitive to heat.
• Undergo denaturation and coagulation upon heating to 80 °C (Kwon et al., 1996)
• Several endothermic transitions in the range of high temperature (80 °C to 120 °C)
• Varying thermal denaturation behavior and complex protein composition of coconut proteins (Kwon et al., 1996; Seow & Goh, 1994)
• Heat at high temperatures for a long time, results in
• Denaturation
• Precipitation of proteins in the coconut milk
• Enhanced at the acidic and basic pH regions (Onsaard, Vittayanont, Srigam, & McClements, 2005) [30]
• Coconut protein is more resistant to heat denaturation when present:
• Salts,
• Polyols,
• sugars (Seow & Goh, 1994) [30]

Coconut residue after fluid extraction

• Has a high percentage of dietary fibre
• Soluble 3·41 g/100 g
• Insoluble 34·0 g/100 g [9]
• Suggested to contribute to many of coconut’s health benefits [9]

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