Department of Food Sciences and Technology, Laboratory of Biotechnology and food Microbiology, University Nangui Abrogoua, Abidjan, Cote Divoire, West Africa
Received Date: 26/09/2017; Accepted Date: 30/09/2017; Published Date: 05/10/2017
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Attieke is the major fermented plant food in Côte d'Ivoire. It is a steamed granular cassava (Manihot esculenta Crantz) meal, couscouslike product, with slightly sour taste and whitish colour. Our study is a technical sheet of process of attieke production in cote d’Ivoire. process of attieke production in côte d’Ivoire was : Cassava roots, peeling, pulp washing, grinding, fermentation, wrinding, sieving, drying, winniwing and fibre removal, cooking, packaging and attieke. Attieke not contained coliforms, moulds and anaerobic sulfite reducing bacteria, Salmonella and Echerichia coli. However, the values obtained fall within the standard specifications set for attieke by CODINORM (Côte d'Ivoire standards Board)
Attieke, Process, Cote divoire
Cassava, the enlarged root of Manihot esculenta Crantz, is an important staple food for about 80% of Cote d'Ivoire's estimated population, especially those living in the southern regions . Cassava may be processed by boiling, roasting, drying, or by fermentation, depending on the variety  before eaten. However, the most popular processing method, especially for the varieties which are high in the cyanogenic glucosides, is by fermentation. In Africa, over 90% of the processed cassava are consumed as fermented products , and one of the most popular fermented foods derived from cassava in Cote d'Ivoire is attieke. Attieke, a steamed cassava fermented semolina, is one such fermented cassava product and is of significant importance for an increasing number of people in Cote d'Ivoire  and other countries in the world. Recent data on attieke consumption do not exist, but Aboua et al.  estimated the consumption between 28,000 and 34,000 tons per year, the equivalent of 40,000 and 50,000 tons of fresh cassava. The popularity of attieke to urban dwellers is associated with its cheapness, lower bulk (as compared to other cassava product) and its characteristic of ready to eat food. The processing of cassava into attieke needs several and hard steps. Our study is a technical sheet of process of attieke production in Cote d’Ivoire.
The amino acid that has been shown to affect brain neurotransmission most readily is tryptophan. It is an essential amino acid and precursor of neurotransmitter serotonin and hormone melatonin. Central serotoninergic system is also involved in the regulation of other mood status, including depression. However, a single tryptophan deficient meal has been clearly shown to produce transient depression in normal human. It produces hypnotic like effect, accordingly, it could be considered as a drug not a food.
The used plant material consisted of 12 months-old freshly harvested cassava roots of the bitter variety, IAC cultivar (Improved African Cassava) (Figure 1).
Roots are peeled, cut into pieces and then washed three times with fresh water. The milling takes place in a cooperative mill located in the village. Before milling, 5–10% (w/w) of inoculum, 10% (v/w) water and about 01% (v/w) of palm oil are added and the pieces are ground to a fine paste, which is placed in large bowls. The mash is left to ferment for about 12–15 hours at ambient temperature (30–37°C). After fermentation, the mash is placed in a jute sack and pressed continuously in a hand press for an hour. The press cake is then passed through two sieves to obtain a fine powder. The grains are formed by shaking and rotating the powder in a large bowl. The grains are sun-dried on black plastic canvas or flat bowls for a time period ranging from a few minutes up to half an hour. After drying, fibres and dirt are removed by sprinkling the grains. The grains are poured onto the sieve up to a height of 15–20 cm for steaming for about 20–25 hours on a cauldron filled with boiling water. Attieke obtained is the filled into plastic bags, sealed airtight and sold on local markets or transported in cars at ambient temperature (30–37°C) in other localities (Figures 2-8).
Determination of pH and Total Titrable Acidity (TTA)
Thirty grams of cassava traditional inocula samples were blended with 70 ml of sterile distilled water and filtered through a Whatmanfilter paper. The pH of 30 ml of the filtered solution was determined using a pH-meter (pH-meter P107, Consort, BioblockScientific, Illkirch, France). TTA was determined using the standard method described by Amoa-Awua et al. . Ten millilitres of filtered solution were titrated with NaOH 01 N, using 1% phenolphthalein as indicator. The volume of aliquot used was recorded to determine the amount of acid in the sample. The titrable acidity was calculated as percentage of lactic acid. The determinations were carried out in triplicates and the mean value recorded.
Enumeration and Identification of Spoilage Microorganisms
Preparation of stock solutions, inoculation of agar plates, cultivation and quantification of micro-organisms were carried out according to . For all determinations, 10 g of the traditional cassava inocula samples was homogenized in a stomacher with 90 ml of sterile buffered peptone water (AES Laboratoire, Combourg, France). Tenfold serial dilutions of stomacher fluid were prepared and spread plated for determination of micro-organism counts. Enumeration of coliforms was carried out using plates of Violet Red Bile Lactose agar (VRBL, Merck 10660, Merck, Darmstadt, Germany). The cultures were incubated for 48 h at 30°C for total coliforms and 44°C for faecal coliforms. Yeasts and moulds were enumerated on plates of Sabouraud–chloramphenicol agar (Fluka, Bochemica 89579, Sigma-Aldrich Chemie GmbH, Bangalore, India), incubated at 30°C for 4 days. Aerobic mesophiles were enumerated on plates of plate count agar (PCA Oxoid Ltd, Basingstoke, UK) and incubated at 30°C for 2 days.
Isolation and Identification of Food-borne Pathogens
Staphylococcus aureus was isolated and enumerated according to the method described by Capita et al. . A volume of 01 ml of each dilution was surface plated on Baird-Parker agar (BPA) containing egg yolk tellurite emulsion (Oxoid) and incubated at 37°C for 24 and 48 h .The total number of colonies, colonies with different morphology to those of Staphylococcus aureus was counted. Five colonies from each sample were randomly selected, purified and tested for cell morphology, arrangement of the cells, Gram reaction, catalase activity, oxidase test, ability to produce acid anaerobically in a glucose-containing growth medium, coagulase activity, thermo-stable nuclease activity, acid production from mannitol and acetoin production. Only, the gram positive cocci were identified using the identification schemes proposed by Schleifer . After the identification, the percentages of Staphylococcus aureus and the other strains were calculated. These percentages were later used to correct the results of the counts obtained from each BPA plate.
The quantitative estimation of spores of B. cereus was performed by a standard plate-counting method. Isolations were achieved from heat-treated dilutions by plating on mannitol egg yolk polymyxin B agar . Presumptive colonies of B. cereus were randomly selected based on characteristic colony feature, purified on the same medium and identified by morphological, cultural and biochemical characteristics according to the documented procedures .
The research of Salmonella in cassava traditional inocula, palm oil and water samples were achieved according to the procedure described in the global Salmonella surveillance and laboratory support project of the World Health Organization . From each sample, 25 g was aseptically weighed and macerated in 225 ml of buffered peptone water (Oxoid) and incubated at 37°C for 24 h. A selective enrichment in Tetrathionate broth (Muller-Kauffmann) and Rappaport Vassiliadis soy peptone broth using 1 ml of previously incubated buffered peptone water was achieved at 37°C for 24 h, followed by a subcultivation on Salmonella Shigella agar incubation at 35°C for 24– 48 hours . Colourless, transparent and with a black centre colonies were further identified using biochemical tests.
Descriptive statistics for microbiological data were calculated with Excel (Microsoft, Redmond, WA, USA). All statistical analyses were implemented in STATISTICA for Windows ver. 10 (StatsoftIberica, Lisbon, Portugal). Parametric tests (one-way variance analysis with Duncan’s test) at 5% significance level were performed to determine whether there were significant differences between markets regarding microbiological data collected.
In Côte d’Ivoire; attieke plays an important role in the population diet. It is part of the diet of many peoples. It is a typically Ivorian food, whose annual local consumption is estimated at over 450000 tons . Attieke production in Côte d’Ivoire is usually prepared by method described above (Figure 1). Attieke just after cooking and attieke packed had acidic pH. The production of attieke depends on a fermentation step which gives an intermediate product (fermented paste) of acid pH. Other unit operations that result in the finished product do not cause significant pH changes . pH values were 4.37 and 4.36, respectively. The titratable acidity values were respectively 2.44% and 1.78%. However, the values obtained fall within the standard specifications set for attieke by CODINORM (Côte d'Ivoire standards Board) (4–5 for pH) and are also similar to the results of Coulin et al. . Just after steaming and packaging in plastic bags, attiéké did not contain coliforms, moulds and anaerobic sulfite reducing bacteria, Salmonella and Escherichia coli (Table 1).
Table 1. pH, total titratable acidity and microbial population in cassava traditional inocula used in attieke process.
|Titratable acidity (%)||1.67± 0.2|
|Bacilli (CFU.g-1)||(1.41± 3.2)103|
|Total coliforms (CFU.g-1)||Ab|
|Faecal coliforms (CFU.g-1)||Ab|
The absence of Salmonella,E. coli and anaerobic sulfite reducing bacteria in attieke samples could be due to the low pH. In fact, the combined effect of organic acids produced during the fermentation period may possibly exert bacteriostatic effect on spoilage organisms and pathogens that might be present [15,16]. They all contained Bacillus spore at mean loads of (1.41 ± 3.2)103. Due to the low level of microbial detection, these attieke samples were of satisfying quality in regard to the standards recommended by CODINORM.
Attieke is a typically Ivorian food. Its production necessarily involves stages of production that pass from the roots of cassava to the cooking of the semolina. The attieke obtained at an acid pH and is of satisfactory microbiological quality.
This work was supported by the International Foundation for Science (IFS) under Grant E/4955-1. The authors gratefully acknowledge all the women attieke producers. There is no conflict of interest concerning this manuscript.