Influence of drying methods on heavy metal composition and microbial load of plantain chips

Figures & data

Plate 1. Use of the solar tent dryer and open sun for drying of plantain chips (Adenitan et al., 2021).

Plate 2. Original image of sun-dried (a) and solar tent-dried (b) plantain chips.

Table 1. Socioeconomic and demographic characteristics of local processors of plantain chips in some parts of Ondo state

	Aponmu	Isinkan	Idi agba	Odode	Alade	Idi araba	Ita olorun	Oniyeu Abusoro	Atosin	Okolo Ajembamibo	Mean value
	Freq/%	Freq/%	Freq/%	Freq/%	Freq/%	Freq/%	Freq/%	Freq/%	Freq/%	Freq/%	(%)
Age 21–30	2/20	0/0	0/0	1/10	0/0	0/0	0/0	0/0	0/0	0/0	3
31–40	4/40	3/30	1/10	1/10	3/30	1/10	3/30	4/40	1/10	4/40	25
41–50	2/20	2/20	3/30	5/50	4/40	6/60	2/20	5/50	6/60	5/50	40
Above 50	2/20	5/50	6/60	3/30	3/30	3/30	5/50	1/10	3/30	1/10	32
Sex
Male	0/0	0/0	0/0	0/0	0/0	3/30	0/0	2/20	0/0	3/30	8
Female	10/100	10/100	10/100	10/100	10/100	7/70	10/100	8/80	10/100	7/70	92
Marital status
Single	0/0	0/0	0/0	0/0	0/0	0/0	0/0	0/0	0/0	0/0	0
Married	9/90	10/100	8/80	8/80	9/90	10/100	10/100	9/90	7/70	10/100	90
Divorced	0/0	0/0	0/0	1/10	0/0	0/0	0/0	0/0	0/0	0/0	1
Widowed	1/10	0/0	2/20	1/10	1/10	0/0	0/0	1/10	3/30	0/0	9
Ethnic group
Yoruba	10/100	9/90	9/90	10/100	10/100	10/100	9/90	8/80	10/100	9/90	94
Igbo	0/0	1/10	1/10	0/0	0/0	0/0	1/10	1/10	0/0	0/0	4
Others (Urobo)	0/0	0/0	0/0	0/0	0/0	0/0	0/0	1/10	0/0	1/10	2
Education level Primary	4/40	5/50	3/30	4/40	2/20	0/0	5/50	4/40	1/10	4/40	32
Secondary	5/50	4/40	6/60	5/50	7/70	9/90	4/40	5/50	7/70	6/60	58
Tertiary	0//0	1/10	0/0	0/0	0/0	0/0	1/10	0/0	0/0	0/0	2
Not educated	1/10	0/0	1/10	1/10	1/10	1/10	0/0	1/10	2/20	0/0	8
Minor Occupation
Yes	4/40	5/50	6/60	5/50	5/50	2/20	5/50	4/40	6/60	3/30	45
No	6/60	5/50	4/40	5/50	5/50	8/80	5/50	6/60	4/40	7/70	55
Major Occupation
Yes	6/60	5/50	4/40	5/50	5/50	8/80	5/50	6/60	4/40	7/70	55
No	4/40	5/50	6/60	5/50	5/50	2/20	5/50	4/40	6/60	3/30	45

Table 2. Perception of local processors on plantain chip processing

	Aponmu	Isinkan	Idi agba	Odode	Alade	Idi araba	Ita olorun	Oniyeu Abusoro	Atosin	Okolo Ajembamibo	Mean value
	Freq/%	Freq/%	Freq/%	Freq/%	Freq/%	Freq/%	Freq/%	Freq/%	Freq/%	Freq/%	(%)
Experience in drying < 5 years	1/10	0/0	3/30	1/10	2/20	0/0	0/0	0/0	2/20	0/0	9
5–10 years	5/50	2/20	4/40	5/50	2/20	3/30	2/20	5/50	4/40	4/40	36
11–15 years	1/10	5/50	1/10	1/10	5/50	4/40	5/50	2/20	2/20	2/20	28
16–20 years	1/10	0/0	2/20	0/0	0/0	0/0	0/0	2/20	0/0	3/30	8
Above 20 years	2/20	3/30	0/0	3/30	1/10	3/30	3/30	1/10	2/20	1/10	19
Variety used
Agbagba	8/80	9/90	9/90	7/70	8/80	7/70	9/90	3/30	6/60	8/80	74
Agbagba and Panbo	2/20	1/10	1/10	3/30	2/20	3/30	1/10	5/50	4/40	2/20	24
Agbagba and Paranta	0/0	0/0	0/0	0/0	0/0	0/0	0/0	2/20	0/0	0/0	2
Drying time
3–4 days	0/0	0/0	0/0	0/0	0/0	0/0	0/0	0/0	1/10	0/0	1
4 days	1/10	0/0	1/10	0/0	0/0	0/0	0/0	0/0	0/0	0/0	2
4–5 days	1/10	1/10	0/0	0/0	1/10	1/10	1/10	0/0	3/30	2/20	10
5 days	5/50	4/40	8/80	1/10	5/50	2/20	4/40	1/10	6/60	0/0	36
5–6 days	3/30	3/30	1/10	4/40	3/30	5/50	3/30	1/10	0/0	1/10	24
6 days	0/0	1/10	0/0	5/50	1/10	1/10	1/10	7/70	0/0	6/60	22
6–7 days	0/0	1/10	0/0	0/0	0/0	1/10	1/10	1/10	0/0	1/10	5
Source of plantain
Farm	6/60	1/10	2/20	5/50	1/10	8/80	1/10	7/70	0/0	9/90	40
Market	1/10	3/30	3/30	1/10	3/30	0/0	3/30	0/0	3/30	0/0	17
Farm and Market	3/30	6/60	5/50	4/40	6/60	2/20	6/60	3/30	7/70	1/10	43
Materials for chips preservation
Dried pepper	4/40	1/10	2/20	1/10	1/10	3/30	1/10	0/0	3/30	5/50	21
Phostoxin	0/0	0/0	2/20	0/0	0/0	0/0	0/0	0/0	0/0	0/0	2
Nil	6/60	9/90	6/60	9/90	9/90	7/70	9/90	10/100	7/70	5/50	77

Table 3. Constraints and problems encountered during processing and storage of plantain chips

Type of constraint/problem	Aponmu	Isinkan	Idi agba	Odode	Alade	Idi araba	Ita olorun	Oniyeu Abusoro	Atosin	Okolo Ajembamibo	Mean Value (%)
	Freq/%	Freq/%	Freq/%	Freq/%	Freq/%	Freq/%	Freq/%	Freq/%	Freq/%	Freq/%
Time consuming and laborious	9/90	5/50	7/70	10/100	10/100	10/100	10/100	10/100	10/100	10/100	91
Tedious peeling and drying	8/80	10/100	9/90	7/70	8/80	10/100	10/100	10/100	9/90	9/90	91
Insects and weevil infestation during storage	1/10	3/30	1/10	0/0	6/60	0/0	1/10	0/0	2/20	0/0	14
Transportation from farm to processing point	2/20	5/50	4/40	2/020	2/20	0/0	0/0	0/0	3/30	0/0	18
Monitoring of drying process to prevent contamination	1/10	0/0	3/30	1/10	0/0	0/0	0/0	0/0	0/0	2/20	8
Stressful process	4/40	3/30	4/40	6/60	1/10	8/80	4/40	4/40	1/10	6/60	40
Extended drying time during rainy season	1/10	0/0	0/0	0/0	0/0	0/0	0/0	0/0	0/0	0/0	1
Weather condition	0/0	0/0	0/0	0/0	0/0	0/0	1/10	0/0	0/0	0/0	1

Table 4. Heavy metals composition of dried plantain chips

Samples	Cadmium (mg/kg)	Cobalt (mg/kg)	Nickel (mg/kg)	Lead (mg/kg)	Copper (mg/kg)	Zinc (mg/kg)	Manganese (mg/kg)	Iron (mg/kg)
Solar tent-dried
Agbagba	ND	ND	0.27 ± 0.02^a-^c	0.05 ± 0.05^fg	2.62 ± 0.42^c-^f	5.15 ± 0.90^b	10.08 ± 5.41^ab	9.99 ± 1.00^e
Bobby tannap	0.03 ± 0.02^de	0.01 ± 0.02^bc	0.21 ± 0.02^c	ND	2.08 ± 1.49^d-^f	3.78 ± 1.01^b	2.08 ± 0.19^c	11.07 ± 1.29^c-^e
Mbi egome	0.04 ± 0.00 ^cd	ND	0.21 ± 0.02^c	0.11 ± 0.12^fg	1.29 ± 0.39 ^f	3.62 ± 0.19^b	2.18 ± 0.18^c	9.41 ± 0.83^e
Pita 23	0.04 ± 0.01^c-^e	ND	0.02 ± 0.02^a-^c	0.11 ± 0.02 ^fg	4.42 ± 0.02^ab	4.83 ± 0.04^b	5.85 ± 0.02^bc	11.87 ± 0.25^c-^e
Open sun-dried
Agbagba	0.07 ± 0.02^ab	0.07 ± 0.02^a	0.31 ± 0.06^ab	ND	5.00 ± 1.92^a	4.83 ± 0.68^b	9.87 ± 5.73^ab	10.25 ± 0.51^e
Bobby tannap	0.08 ± 0.00^a	0.03 ± 0.02^b	0.33 ± 0.17^a	0.29 ± 0.08^c-^e	3.00 ± 2.05^b-^f	5.27 ± 3.04^b	2.19 ± 0.45^c	9.83 ± 0.27^e
Mbi egome	0.07 ± 0.02^ab	ND	0.24 ± 0.00^bc	0.45 ± 0.10^ab	1.79 ± 0.48^ef	3.73 ± 0.34^b	2.19 ± 0.29^c	8.92 ± 1.53^e
Pita 23	0.04 ± 0.01^c-^e	ND	0.23 ± 0.02^c	0.50 ± 0.02^a	4.77 ± 0.02^a	4.27 ± 0.04^b	6.24 ± 0.04^a-^c	10.95 ± 0.03^de
Locally processed
Akure South LGA
Aponmu	0.05 ± 0.02^bc	ND	0.25 ± 0.02^bc	0.32 ± 0.08 ^cd	4.16 ± 1.89^a-^c	7.74 ± 5.07^ab	12.11 ± 6.19^a	25.75 ± 10.97^a
Isinkan	0.07 ± 0.02^ab	ND	0.21 ± 0.02^c	0.32 ± 0.00 ^cd	3.69 ± 0.49^a-^d	4.64 ± 0.55^b	10.19 ± 6.14^ab	16.62 ± 2.35^a-^e
Idi agba	0.04 ± 0.00 ^cd	ND	0.24 ± 0.00^bc	0.36 ± 0.00^b-^d	3.38 ± 0.39^a-^e	4.56 ± 0.49^b	10.93 ± 1.71^ab	14.72 ± 0.89^b-^e
Idanre LGA
Odode	0.05 ± 0.02^bc	ND	0.23 ± 0.02^c	0.47 ± 0.15^ab	3.80 ± 1.58^a-^d	11.16 ± 7.40^a	8.22 ± 2.43^a-^c	23.54 ± 6.60^ab
Alade	0.04 ± 0.00 ^cd	ND	0.24 ± 0.04^bc	0.40 ± 0.04^a-^c	4.27 ± 1.17^a-^c	4.55 ± 0.47^b	10.12 ± 3.03^ab	17.32 ± 1.64^a-^e
Idi araba	0.04 ± 0.02^de	ND	0.21 ± 0.02^c	0.17 ± 0.06^ef	3.29 ± 0.26^a-^e	4.99 ± 1.57^b	9.10 ± 2.06^ab	21.75 ± 6.17^a-^c
Ita olohun	ND	ND	0.24 ± 0.04^bc	0.09 ± 0.02^fg	4.25 ± 0.88^a-^c	4.60 ± 1.28^b	8.70 ± 0.87^ab	21.52 ± 8.67^a-^d
Oniyeu Abusoro	0.01 ± 0.02^ef	ND	0.25 ± 0.02^bc	0.08 ± 0.07^fg	3.98 ± 0.64^a-^c	8.02 ± 6.11^ab	12.04 ± 3.24^ab	25.96 ± 10.10^a
Atosin	ND	ND	0.31 ± 0.05^ab	ND	3.83 ± 0.52^a-^c	3.95 ± 0.43^b	8.50 ± 3.05^ab	23.21 ± 8.02^ab
Okolo Ajembamibo	ND	ND	0.20 ± 0.04^c	0.24 ± 0.21^de	2.74 ± 0.59^b-^f	4.70 ± 1.66^b	11.71 ± 7.71^ab	23.53 ± 17.13^ab
p Varieties	NS	***	*	*	*	NS	**	NS
p Treatment	**	***	NS	**	NS	NS	NS	NS
p Varieties x Treatment	NS	***	NS	NS	NS	NS	NS	NS

Mean values with the same superscript within a column is not significantly different (p > 0.05)

ND: Not detected, *p < 0.05, **p < 0.01, ***p < 0.001, NS-Not significant (p > 0.05); LGA- Local Government Area

Table 5. Microbial assessment of dried plantain chips

Samples	Bacterial count (cfu/g × 10^4)	Fungi count (cfu/g × 10^3)	Total Microbial count (cfu/g)	Fungi intercepted
Solar tent-dried chips
Agbagba	0.86 ± 0.01 l	0.20 ± 0.01e	4.15x10^3 ± 1.41 j	Penicillium spp, Aspergillus flavus, Aspergillus tamarii, Aspergillus Niger
Bobby tannap	0.96 ± 0.01k	0.10 ± 0.04 f	1.97x10^3 ± 2.12 l	Penicillium spp
Mbi egome	0.20 ± 0.03 m	0.00 ± 0.03 g	2.03x10^3 ± 2.83kl	Nil
Pita 23	2.15 ± 0.01d	0.60 ± 0.04c	2.10x10^3 ± 16.26kl	Rhizopus spp
Open sun-dried chips
Agbagba	2.15 ± 0.01d	0.20 ± 0.02e	2.20x10^4 ± 212.13 f	Penicillium spp, Rhizopus spp, Fusarium verticillioides, Aspergillus Niger
Bobby tannap	2.80 ± 0.07b	1.30 ± 0.01a	2.80x10^4 ± 70.71d	Aspergillus Niger, Rhizopus spp,
Mbi egome	2.01 ± 0.01 f	0.00 ± 0.01 g	2.01x10^4 ± 70.71 g	Nil
Pita 23	1.13 ± 0.01 j	0.20 ± 0.01e	1.30x10^4 ± 141.42 h	Rhizopus spp, Penicillium spp
Locally processed chips
Akure South LGA
Aponmu	2.58 ± 0.01c	0.70 ± 0.03b	2.70x10^4 ± 212.13e	Rhizopus spp, Aspergillus Niger, Aspergillus flavus, Rhizopus
Isinkan	2.08 ± 0.01e	0.40 ± 0.01d	2.85x10^3 ± 3.54jk	Rhizopus spp, Aspergillus flavus
Idi agba	3.09 ± 0.01a	0.20 ± 0.02e	3.10x10^4 ± 141.42c	Rhizopus spp
Idanre LGA
Odode	0.89 ± 0.02 l	0.20 ± 0.02e	9.50x10^3 ± 14.14i	Rhizopus spp
Alade	1.34 ± 0.01 h	0.20 ± 0.01e	9.00x10^4 ± 707.11a	Rhizopus spp
Idi araba	1.38 ± 0.01 gh	0.20 ± 0.02e	7.00x10^4 ± 1414.21b	Aspergillus flavus
Ita olohun	1.19 ± 0.01i	0.20 ± 0.03e	2.86x10^3 ± 3.54jk	Nil
Oniyeu Abusoro	2.21 ± 0.01d	0.20 ± 0.01e	1.79x10^3 ± 2.83 l	Aspergillus tamarii, Aspergillus flavus, Rhizopus spp
Atosin	1.39 ± 0.01g	0.20 ± 0.02e	1.49x10^3 ± 2.12 l	Aspergillus Niger, Aspergillus spp, Aspergillus tamarii, Rhizopus spp
Okolo Ajembamibo	1.37 ± 0.01gh	0.10 ± 0.02f	3.00x10^3 ± 141.42 j	Monilla spp, Aspergillus Niger, Penicillium spp
p Varieties	NS	**	NS
p Treatment	NS	NS	NS
p Varieties × Treatment	**	***	NS

Each value represents the mean of triplicate samples; CFU/g: Colony Forming Unit/gram, LGA: Local Government Area

Adenitan, A. A., Awoyale, W., Akinwande, B. A., Maziya-Dixon, B., & Sulyok, M. (2021). Mycotoxin profiles of solar tent-dried and open sun-dried plantain chips. Food Control, 119(4), 107–467. https://doi.org/10.1016/j.foodcont.2020.107467

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