Physicochemical, microbial, and aflatoxin analyses of selected high-quality cassava flour (HQCF) from the major markets of Zambia

Figures & data

Table 1. High-quality cassava flour (HQCF) samples collected from different markets with sample code

Sample Code	Brand Name	Manufacturer/Supplier
CM 01	Standa Cassava Meal	Standa Enterprises Ltd
CM 02	Nsamachu Cassava Meal	Nsamachu Trading
CM 03	One Banja Cassava Meal	One Banja Co. Ltd
CM 04	Food Plus Cassava Meal	Food Plus Zambia Ltd
CM 05	NKHOSI Cassava Meal	Tradex Ltd
CM 06	Super Meal Cassava Meal	Dundumweezi Enterprises
CM 07	Super White Cassava Meal	Namando Investments (Z) Ltd
CM 08	Soweto Market Cassava Meal	Suppliers from Luapula, Mongu, Mkushi, Mansa districts, DRC Exporter
CM 09	ZYA HQCF	Zambia Youth Agribusiness (ZYA) cassava processing center

Table 2. Chemical composition of commercial high-quality cassava flour from major Lusaka markets

Sample ID	% MC	% Ash	% Fat	% Crude fibre	% Protein	% CHO	% Starch	% Sugar	% Amylopectin	% Amylose
CM 01	10.72 ± 0.09^b	1.58 ± 0.01^d	0.68 ± 0.08^a	2.86 ± 0.06^bc	2.17 ± 0.41^a	81.98 ± 0.63^de	61.31 ± 0.08 ^f	3.23 ± 0.02 ^c	77.99 ± 0.06 ^c	22.01 ± 0.06^d
CM 02	12.52 ± 0.03 ^c	1.45 ± 0.47 ^c	0.95 ± 0.35^a	2.34 ± 0.04^abc	1.45 ± 0.05^a	81.28 ± 0.28^de	41.06 ± 0.43^a	5.34 ± 0.08 ^g	77.04 ± 0.06^b	22.95 ± 0.06^e
CM 03	14.20 ± 0.03 ^g	2.07 ± 0.11 ^f	0.67 ± 0.02^a	2.19 ± 0.04^ab	1.76 ± 0.36^a	79.10 ± 0.24^ab	42.38 ± 0.57^b	4.36 ± 0.00 ^f	78.30 ± 0.06^d	21.69 ± 0.06 ^c
CM 04	10.90 ± 0.04^b	2.08 ± 0.04 ^f	0.82 ± 0.20^a	2.45 ± 0.26^abc	1.54 ± 0.20^a	82.19 ± 0.07^de	47.06 ± 0.49^e	5.38 ± 0.08 ^g	78.43 ± 0.11^e	21.57 ± 0.11^b
CM 05	12.43 ± 0.02 ^c	1.86 ± 0.03^e	1.01 ± 0.58^a	2.36 ± 0.05^abc	1.03 ± 0.08^a	81.30 ± 0.54^cde	45.41 ± 0.29^d	3.94 ± 0.00^e	78.19 ± 0.11^d	21.81 ± 0.11 ^c
CM 06	12.84 ± 0.15^d	1.36 ± 0.07 ^c	0.84 ± 0.25^a	2.99 ± 0.61 ^c	3.87 ± 0.39^b	78.08 ± 1.33^a	47.58 ± 0.45^e	2.88 ± 0.07^b	78.74 ± 0.11 ^f	21.25 ± 0.11^a
CM 07	13.76 ± 0.02 ^f	1.30 ± 0.02^b	1.23 ± 0.00^a	1.87 ± 0.03^a	1.98 ± 0.93^a	79.86 ± 0.89^bc	43.82 ± 0.29 ^c	2.27 ± 0.00^a	78.46 ± 0.06^e	21.53 ± 0.06^b
CM 08	13.19 ± 0.87^e	1.12 ± 0.04^a	1.08 ± 0.11^a	2.13 ± 0.49^a	1.55 ± 0.21^a	80.93 ± 0.21 ^cd	63.66 ± 0.07 ^g	2.30 ± 0.07^a	77.20 ± 0.06^b	22.79 ± 0.06^e
CM 09	10.51 ± 0.18^a	1.09 ± 0.04^a	1.23 ± 0.01^a	2.97 ± 0.00 ^c	1.50 ± 0.69^a	82.70 ± 0.92^e	61.33 ± 0.49 ^f	3.72 ± 0.07^d	76.61 ± 0.11^a	23.38 ± 0.11 ^f
Min	10.51	1.09	0.67	1.87	1.03	78.08	41.06	2.27	76.61	21.25
Max	14.20	2.08	1.23	2.99	3.87	82.70	63.66	5.38	78.74	23.38
Mean	12.34	1.55	0.95	2.47	1.87	80.83	50.40	3.71	77.89	22.11
SD	1.27	0.36	0.27	0.42	0.84	1.52	8.52	1.10	0.70	0.70
CV (%)	10.31	23.27	28.38	17.09	44.66	1.88	16.91	29.66	0.90	3.18

Values are means and standard deviation (±) of replicate determination. Values with a different superscript in the same column are significantly different at p < 0.05. MC = moisture content, CHO = total carbohydrate.

Table 3. Functional properties of commercial high-quality cassava flour from major Lusaka markets

Sample ID	Bulk density(g/ml)	% Dispersibility	Swelling power	% Solubility	Water absorption capacity
CM 01	0.37 ± 0.26^a	63.00 ± 1.41^a	7.42 ± 0.01^abc	149.55 ± 0.41^e	5.63 ± 0.26^bc
CM 02	0.36 ± 0.02^a	71.00 ± 1.41^e	7.92 ± 0.34^d	139.14 ± 0.18^d	4.29 ± 0.61^ab
CM 03	0.59 ± 0.01^d	70.00 ± 0.00^de	7.83 ± 0.05 ^cd	114.76 ± 8.71^b	3.64 ± 0.05^a
CM 04	0.66 ± 0.03^e	66.00 ± 0.00^b	7.54 ± 0.05^bcd	149.68 ± 0.22^e	5.08 ± 0.23^ab
CM 05	0.54 ± 0.03 ^c	68.50 ± 0.71 ^cd	7.83 ± 0.19 ^cd	136.20 ± 0.22^d	4.45 ± 0.09^ab
CM 06	0.43 ± 0.03^b	67.00 ± 0.00^bc	6.91 ± 0.18^a	129.27 ± 0.12 ^c	7.31 ± 0.06 ^cd
CM 07	0.64 ± 0.01^e	70.80 ± 0.28^e	7.81 ± 0.19 ^cd	107.18 ± 0.59^a	8.84 ± 0.59^d
CM 08	0.34 ± 0.01^a	70.00 ± 0.00^de	7.35 ± 0.07^ab	126.02 ± 1.01 ^c	8.60 ± 1.86^d
CM 09	0.66 ± 0.00^e	66.00 ± 0.00^b	9.96 ± 0.21^e	169.96 ± 0.31 ^f	8.63 ± 1.04^d
Min	0.34	63.00	6.91	107.18	3.61
Max	0.66	71.00	9.96	169.96	8.84
Mean	0.51	68.03	7.84	135.80	6.28
SD	0.13	2.63	0.76	18.18	2.04
CV (%)	25.57	3.87	9.67	13.39	32.49

Values are means and standard deviation (±) of replicate determination. Values with a different superscript in the same column are significantly different at p < 0.05.

Table 4. Pasting properties of commercial high-quality cassava flour from major Lusaka markets

Sample ID	Peak viscosity (RVU)	Trough viscosity (RVU)	Breakdown viscosity (RVU)	Final viscosity (RVU)	Setback viscosity (RVU)	Peak Time (min)	Pasting Temp (^oC)
CM 01	332.46 ± 105.65^a	180.96 ± 38.01^a	151.50 ± 67.65^a	245.71 ± 50.49^a	64.75 ± 12.49^ab	4.67 ± 0.19^bcd	71.85 ± 1.13^ab
CM 02	511.91 ± 4.95 ^c	255.83 ± 2.59 ^c	256.08 ± 2.36 ^c	322.38 ± 5.01^d	66.54 ± 2.42^ab	4.47 ± 0.09^abc	73.50 ± 0.00 ^cd
CM 03	439.54 ± 27.40^bc	253.21 ± 1.00 ^c	186.33 ± 26.39^ab	323.25 ± 2.71^d	70.04 ± 3.71^ab	4.83 ± 0.24^d	73.13 ± 0.53^bc
CM 04	418.50 ± 14.61^abc	229.71 ± 7.13^bc	188.79 ± 7.48^ab	293.29 ± 6.07^bcd	63.58 ± 1.06^ab	4.77 ± 0.14 ^cd	71.48 ± 0.60^a
CM 05	418.88 ± 3.95^abc	203.86 ± 1.83^ab	215.00 ± 5.77^abc	268.00 ± 0.71^abc	64.13 ± 1.12^ab	4.37 ± 0.05^ab	73.13 ± 0.67^bc
CM 06	361.21 ± 36.12^ab	186.75 ± 8.25^a	174.46 ± 27.87^ab	257.88 ± 8.78^ab	71.13 ± 0.53^ab	4.60 ± 0.09^bcd	71.55 ± 0.57^a
CM 07	373.96 ± 3.12^ab	207.54 ± 1.00^ab	166.42 ± 2.12^ab	272.58 ± 3.77^abc	65.04 ± 2.77^ab	4.67 ± 0.09^bcd	73.55 ± 0.07 ^cd
CM 08	429.92 ± 25.22^abc	205.29 ± 11.84^ab	224.63 ± 13.38^bc	266.08 ± 14.73^abc	60.79 ± 2.89^a	4.47 ± 0.19^abc	74.78 ± 0.60^d
CM 09	650.75 ± 0.00^d	234.75 ± 0.00^bc	416.00 ± 0.00^d	309.67 ± 0.00 ^cd	74.92 ± 0.00^b	4.20 ± 0.00^a	71.05 ± 0.00^a
Min	332.46	180.96	151.50	245.71	63.58	4.20	71.05
Max	650.75	255.83	416.00	322.38	74.92	4.83	74.78
Mean	437.46	217.55	219.91	284.31	66.77	4.56	72.67
SD	94.12	27.41	77.94	29.96	5.30	0.21	1.24
CV(%)	21.52	12.60	35.44	10.54	7.94	4.70	1.71

RVU = Rapid Visco Unit, SD = Standard deviation, CV = Coefficient of variation

Values are means and standard deviation (±) of replicate determination. Values with a different superscript in the same column are significantly different at p < 0.05.

Table 5. Anti-nutrient properties of commercial high-quality cassava flour from major Lusaka markets

SampleID	Tannin (%)	Phytate(mg/g)	CNP (mg HCN/kg)
CM 01	0.53 ± 0.02^ab	0.27 ± 0.05^ab	2.87 ± 0.04^e
CM 02	1.17 ± 0.38 ^c	0.44 ± 0.00^bc	2.91 ± 0.02^e
CM 03	0.86 ± 0.01^bc	0.13 ± 0.05^a	1.92 ± 0.02^d
CM 04	0.66 ± 0.05^ab	0.40 ± 0.05^bc	1.13 ± 0.06^a
CM 05	0.64 ± 0.21^ab	0.40 ± 0.05^bc	3.52 ± 0.04 ^f
CM 06	0.57 ± 0.04^ab	0.47 ± 0.05 ^c	1.69 ± 0.05 ^c
CM 07	0.42 ± 0.01^a	0.47 ± 0.14 ^c	1.73 ± 0.02 ^c
CM 08	0.56 ± 0.08^ab	0.47 ± 0.14 ^c	1.31 ± 0.00^b
CM 09	0.40 ± 0.01^a	0.37 ± 0.00^bc	1.71 ± 0.02 ^c
Min	0.40	0.13	1.13
Max	1.17	0.57	3.52
Mean	0.65	0.38	2.09
SD	0.25	0.12	0.77
CV (%)	38.79	31.26	36.78

CNP = Cyanogenic potential

Values are means and standard deviation (±) of replicate determination. Values with a different superscript in the same column are significantly different at p < 0.05.

Table 6. Correlation coefficients of proximate, anti-nutritional, functional and pasting properties of high-quality cassava flour in the Lusaka market

Parameter	MC	Ash	Fat	Crude fiber	Protein	CHO	Starch	Sugar	Amylopectin	Amylose
Tannin	0.232	0.332	—0.046	—0.185	–0.161	–0.125	0.530*	0.632**	–0.106	0.106
Phytate	− 0.029	− 0.470*	0.369	–0.160	0.201	0.004	0.032	–0.257	–0.083	0.083
CNP	− 0.071	0.186	–0.108	0.074	–0.241	0.147	–0.214	0.199	–0.061	0.061
Bulk density		0.290	0.231	–0.131	–0.211	0.127	–0.264	0.187	0.196	–0.196
Dispersibility	0.805**	–0.096	0.278	0.677**	–0.170	–0.419	–0.524*	–0.031	–0.064	0.064
SP	–0.387	–0.302	0.414	0.216	–0.416	0.492*	0.232	0.164	–0.661**	0.661**
Solubility	–0.935**	–0.100	0.034	.642**	–0 .201	0.733**	0.490*	0.381	–0.530*	0.530*
WAC	–0.035	–0.795**	0.530*	–017	0.291	–0.031	0.527*	–0.741**	–0.226	0.226
Peak 1	–0.294	–0.303	0.357	0.175	–0.407	0.430	0.162	0.326	–0.768**	0.768**
Trough 1	0.129	0.242	0.013	–0.248	–0.459	0.154	–0.398	0.654**	–0.373	0.373
Break down	–0.400	–0.451	0.426	0.299	–0.330	0.466	0.335	0.163	–0.797**	0.797**
Final viscosity	0.097	0.198	0.027	–0.165	–0.394	0.130	–0.371	0.612**	–0.368	0.368
Setback	–0.119	–0.128	0.085	0.346	0.145	–0.061	–0.038	0.077	–0.150	0.150
Peak Time	0.311	0.555*	–0.436	–0.248	0.255	–0.387	–0.362	0.102	0.649**	–0.649**
Pasting Temp	0.673**	–0.132	0.092	–0.703**	–0.303	–0.187	–0.117	–0.257	–0.122	0.122

*** = significant at p < 0.001, ** = significant at p < 0.01, * = significant at p < 0.05, MC = moisture content, CHO = total carbohydrate, CNP = Cyanogenic potential, SP = swelling power, WAC = water absorption capacity.

Table 7. Aflatoxins B₁, B₂, G₁, and G₂ (ppb) contents of high-quality cassava flour from Lusaka markets ^a

Sample ID	Aflatoxin (ppb)^a^bc
	B1	B2	G1	G2
CM 01	0	0	0	0
CM 02	0	0	0	0
CM 03	0	0	0	0
CM 04	0	0	0	0
CM 05	0	0	0	0
CM 06	0	0	0	0
CM 07	0	0	0	0
CM 08	0	0	0	0
CM 09	0	0	0	0

^a Recovery of toxin = > 85%.

^b Zero means the aflatoxin level is below the detection limit of the analytical method (1 ppb).

^c Values are means of two subsamples of each sample.

Table 8. Gram staining and KOH reaction of bacterial isolates in high-quality cassava flour from Lusaka market

Bacteria isolate	Gram-stain reaction	KOH reaction
Bac 1	+ ve	– ve
Bac 2	+ ve	– ve
Bac 3	+ ve	– ve
Bac 4	+ ve	– ve
Bac 5	+ ve	– ve
Bac 6	- ve	+ ve

Figure 1. Gram staining reactions of the bacteria isolates (+ve = positive and -ve = negative) from high-quality cassava flour (HQCF) from Lusaka markets

Table 9. Bacterial and fungal isolates detected in the high-quality cassava flour from Lusaka markets

	Fungal growth on APDA		Bacterial growth on PCA						Bacterial growth on NA
sample code	Rhizopus		Bac 1	Bac 2	Bac 3	Bac 4	Bac 5	Bac 6	Bac 1	Bac 2	Bac 3	Bac 4	Bac 5	Bac 6
CM 01	-ve		-ve	-ve	-ve	-ve	-ve	-ve	-ve	-ve	-ve	-ve	-ve	-ve
CM 02	-ve		+ve	-ve	-ve	-ve	-ve	+ve	+ve	-ve	+ve	+ve	+ve	-ve
CM 03	-ve		+ve	-ve	+ve	+ve	+ve	+ve	+ve	-ve	+ve	+ve	+ve	-ve
CM 04	+ve		-ve	+ve	-ve	-ve	-ve	-ve	+ve	-ve	-ve	-ve	-ve	-ve
CM 05	-ve		+ve	-ve	-ve	-ve	-ve	+ve	+ve	+ve	-ve	-ve	+ve	-ve
CM 06	+ve		-ve	-ve	-ve	-ve	+ve	-ve	+ve	+ve	+ve	+ve	-ve	-ve
CM 07	+ve		-ve	-ve	-ve	-ve	-ve	-ve	+ve	-ve	-ve	-ve	-ve	-ve
CM 08	+ve		+ve	-ve	+ve	+ve	+ve	+ve	-ve	-ve	+ve	+ve	+ve	-ve
CM 09		-ve	+ve	-ve	+ve	+ve	-ve	+ve	+ve	+ve	+ve	+ve	-ve	-ve

Key: +ve = present, -ve = absent

Table 10. Colony-forming unit (CFU) per gram of bacteria and fungi in high-quality cassava flour from the Lusaka markets

	Fungal counts on acidified potato dextrose agar (CFU)			Bacterial counts on plate count agar (CFU)			Bacterial counts on nutrient agar (CFU)
Sample code	Average colony count (10^−ve3)	Calculated CFU (10^−ve3)	Logarithmic notation of CFU (10^−ve3)	Average colony count (10^3)	Calculated CFU (10^−ve3)	Logarithmic notation of CFU (10^−ve3)	Average colony count (10^−ve3)	Calculated CFU (10^−ve3)	Logarithmic notation of CFU (10^−ve3)
CM 01	0	0	0	1	10 000	1 × 10^4	0	0	0
CM 02	0	0	0	28	280,000	2.8 × 10^5	2	20,000	2 × 10^4
CM 03	0	0	0	26	260,000	2.6 × 10^5	80	800,000	8 × 10^5
CM 04	1	10 000	1 × 10^4	3	30 000	3 × 10^4	4	40,000	4 × 10^4
CM 05	0	0	0	8	80 000	8 × 10^4	9	90,000	9 × 10^4
CM 06	1	10 000	1 × 10^4	0	0	0	1	10,000	1 × 10^4
CM 07	1	10 000	1 × 10^4	20	200,000	2 × 10^5	TNTC	TNTC	TNTC
CM 08	1	10 000	1 × 10^4	9	90,000	9 × 10^4	67	670,000	6.7 × 10^5
CM 09	0	0	0	51	510,000	5.1 × 10^5	47	470,000	4.7 × 10^5

Key: TNTC = too numerous to count, CFU = Colony-forming Unit