Prebiotic efficacy of coconut kernel cake’s soluble crude polysaccharides on growth rates and acidifying property of probiotic lactic acid bacteria in vitro

Figures & data

Figure 1. Coconut tree, coconut kernel and coconut kernel cake.

Figure 2. Chemical composition of CKC.

Table 1. Extraction yield percentage of CKC soluble crude polysaccharide.

Types of solvents	pH	CKC soluble crude polysaccharide yield (%)
Hot water	7	1.33 ± 0.30^b
1% Citric acid	2.5	1.38 ± 0.26^b
1% NaOH	12	2.90 ± 0.36^a

Note: ^a,b Values indicated with different superscript letters are statistically significantly different (P < 0.05).

Values are given as means ± SD taken from three different samples (n = 3).

Table 2. Total carbohydrate and protein contents and solubility rate of CKC crude soluble polysaccharides.

Soluble polysaccharide of CKC	Chemical parameters
	Total carbohydrates (%)	Protein (%)	Solubility rate (%)
SCPW	43.26 ± 0.80^c	0.54 ± 0.05^b	99.65 ± 0.14^a
SCPCA	55.36 ± 0.33^a	0.39 ± 0.02^c	99.54 ± 0.16^a
SCPN	42.56 ± 0.64^b	0.63 ± 0.09^a	97.11 ± 0.12^b

Note: ^a,b,c Values indicated with different superscript letters in the same column are statistically significantly different (P < 0.05).

Values are given as means ± SD taken from three different samples (n = 3).

Table 3. Monosaccharide composition of CKC crude soluble polysaccharides.

Monosaccharide compositions	Percentage degree of soluble crude polysaccharide from different solvents
	SCPW (%)	SCPCA (%)	SCPN (%)
Mannose	5.67	31.13	4.52
Galactose	5.27	34.41	4.9
Glucose	78.37	4.98	1.81
Arabinose	3.69	16.63	3.07
Rhamnose	0.89	3.34	0.49
Xylose	0.53	4.09	8.44
Total	94.42	94.59	23.2

Figure 3. FTIR spectra of CKC soluble polysaccharides after extraction using water (SCP_W), citric acid (SCP_CA) and NaOH (SCP_N).

Table 4. Thermal properties of CKC soluble crude polysaccharides.

Samples	Onset temperature, Ton (°C)	End temperature, TC (°C)	Peaks, TM (°C)	Enthalpy change, ΔH (J/g)
SCPW	101.58	151.87	122.88	79.30
SCPCA	109.69	146.33	123.86	75.27
SCPN	114.02	151.01	130.54	136.38

Figure 4. Hydrolysis of FOS, SCP_CA and SCP_W after treatment with artificial human gastric juice.

Note: The error bars represent the range of sample variation between three replicates and the standard deviation.

Figure 5. Hydrolysis of FOS, SCP_W and SCP_CA after treatment with α-amylase.

Note: The error bars represent the range of sample variation between three replicates and the standard deviation.

Table 5. Proliferation of L. plantarum ATCC 8014 and L. rhamnosus ATCC 53103 on SCP_W and SCP_CA in vitro.

Prebiotics	Concentration (%)	L. plantarum ATCC 8014 (CFU/mL)	L. rhamnosus ATCC 53103 (CFU/mL)
Carbohydrate-free MRS (Blank control)	0	1.01 ± 0.01^Ae	0.99 ± 0.04^Ae
Carbohydrate-free MRS + FOS (Positive control)	0.3	1.75 ± 0.29^Ad	1.66 ± 0.15^Ad
	0.5	2.48 ± 0.11^Ac	2.32 ± 0.03^Ac
	0.7	2.51 ± 0.06^Ac	2.50 ± 0.01^Ab
Carbohydrate-free MRS + SCPW	0.3	1.82 ± 0.10^Ad	1.63 ± 0.02^Bd
	0.5	2.77 ± 0.06^Ab	2.41 ± 0.09^Bc
	0.7	2.91 ± 0.14^Ab	2.54 ± 0.30^Bb
Carbohydrate-free MRS + SCPCA	0.3	1.99 ± 0.93^Ad	1.73 ± 0.02^Bd
	0.5	3.06 ± 0.12^Aa	2.58 ± 0.09^Bb
	0.7	3.12 ± 0.14^Aa	2.64 ± 0.05^Ba

Note: ^a,b,c,d,e Values indicated with different small superscript letters in the same column are statistically significantly different (P < 0.05).

^A,B Values indicated with different capital superscript letters in the same row are statistically significantly different (P < 0.05).

Values are given as means ± SD from triplicate determination (n = 3).

Figure 6. Acidifying activity of probiotics in vitro during their growth on SCP_W and SCP_CA after 48-h incubation at 37 °C: L. plantarum ATCC 8014 (a) and L. rhamnosus ATCC 53103 (b).

Note: The error bars represent the range of sample variation between three replicates and the standard deviation.