Effect of autoclaving on the formation of resistant starch from two Nigeria Cassava (Manihot esculenta) varieties

Open Access Journal; Published online: 31 Aug 2018This study evaluated the effect of autoclaving process on the production of resistant starch (RS) from cassava starch. RS was prepared by debranching, autoclaving and storage of cassava starch from two Nigeria varieties (TMS 30572 and TMS 98/0581). Starch suspensions were prepared with different starch water ratios (1:1; 1:3; and 1:5), debranched with isoamylase, autoclaved at 110 and 121◦C for four heat and cool cycles, stored under refrigeration and freezing condition for 48 h. Debranching process increased RS by about 73-78%. Higher RS was obtained at higher temperature and with significant difference (p<0.05) from each other. RS increased with storage time from 6.23 to 9.60 and 22.40 to 25.77 g/100 g for undebranched and debranched samples, respectively, after 48 h. This study indicated the potentials of these Nigeria cassava varieties in the production of RS which could serve as functional food

Determination of an effective maturity index for white yam (Dioscorea rotundata)

Whole small tubers and setts from 15 genotypes of white yam (Dioscorea rotundata) at their post-dormant stage were planted at the beginning of the rainy season in 2003 and 2004. Harvesting was done at monthly intervals from three months after vine emergence (MAVE) till when there was senescence of foliage. Dry matter, sugar and starch contents of both the leaves and yam tubers were monitored during growth to determine an indicator for maturity that could indicate the best time to harvest the tuber. The dry matter content of leaves increased steadily from 3 MAVE (range of 19.31–24.56%) to 5 MAVE (range of 20.86–43.28%). Sharp increase was noticed between 5 MAVE when yellowing of lower leaves was observed, a sign of on-set of senescence, and 6 MAVE (range of 78.16–90.49%), when the leaves were dry and brown. Dry matter content values increased steadily in the tubers with age of plant till senescence of foliage took place. The sugar content of leaves declined between 3 and 4 MAVE, rose at 5 MAVE and dropped again at the time of foliage senescence (6 MAVE). An initial sharp decline in sugar content of the yam tuber of most of the genotypes was observed from 3 to between 4 and 5 MAVE before rising again at 6 MAVE. The starch content of leaves decreased between 3 and 5 MAVE and increased again at 6 MAVE. Dry matter content of leaves could be used as rapid index for determining tuber maturity. The starch content of leaves could also serve as an indicator for determining tuber maturity since the tuber is matured when minimum starch content is obtained in the leaves, which coincided with the time that yellowing of lower leaves of the plant was observed

Food intake among smallholder cassava value chain households

Purpose The purpose of this study is to compare food consumption and dietary diversity in smallholder cassava value chain households (CVCHs) and non-cassava value chain households (non-CVCHs). Design/methodology/approach A total of 572 rural households were selected using multi-stage sampling from Oyo and Kwara states, Southwest Nigeria. Socio-demographic, 24 h dietary recall and food frequency questionnaires were used to collect data. Household Dietary Diversity Score (HDDS) and the Minimum Dietary Diversity for Women of Reproductive Age (MDD-W) were measured. Findings The mean age of respondents was 49.1 ± 17.3 years, 68.3 per cent were female, household sizes ranged from 2-20 with an average of 8 members. Most households consumed monotonous staple-based diets mainly from roots and tubers, cereals and legumes. There was no significant difference in HDDS (6.70 ± 1.37 and 6.77 ± 1.12; p = 0.12) and MDD-W (4.78 ± 1.12 and 4.95 ± 1.16; p = 0.09) for CVCH and non-CVCH respectively. About one-third of all women did not achieve the MDD-W score required for micronutrient adequacy, with the main dietary gap being vitamin A-rich fruits and vegetables. Practical implications The findings suggest that there was no influence of households’ involvement in cassava value chain activities on their pattern of food consumption and dietary diversity. Originality/value While cassava value chain activities have potential for improved livelihoods among its actors, a nutrition-sensitive approach needs to be incorporated to translate this into their improved food consumption, dietary diversity and nutritional (particularly micronutrient) status

Chemical Composition and Antioxidant Activities of Mushroom Species from Different Geographical Locations

Mushrooms have high nutritional and medicinal values and are important sources of protein and fibre, which make them important for plant- based diets. Awareness on the benefits of consumption is important in African countries like Nigeria for increased food security. Six commonly cultivated mushroom species were collected from two locations in Nigeria (Ibadan and Port-Harcourt) and one location in Ghana (Accra). Constituents (proximate and mineral composition, and antioxidant activities) of samples were evaluated and compared. Mushroom properties were identified with locations where cultivated. The protein, fat, ash and fibre contents ranged from 6.13 – 35.84%, 11.63 –19.15%, 2.64 – 12.78%, 3.37 – 6.62%, respectively. A major element was potassium (38.66-463.04 mg/100g), followed by phosphorus (44.05 – 162.08 mg/100g), sodium (20.95 – 71.92 mg/100g), calcium (30.82 – 49.27 mg/100 g) and magnesium (9.80 – 19.88 mg/100 g). Concentrations of trace elements ranged from 0.39 – 2.44 mg/100 g, 0.06 – 0.40 mg/100g, 0.20 – 8.22 mg/100 g, and 0.30 – 4.04 mg/100g for Cu, Mn and Zn, respectively while Pb was not detected. The 1,1-diphenyl-1-picrylhydrazyl and ferric reducing antioxidant power values ranged from 0.28 – 32.15% and 0.17 – 1.92 µmol/g, respectively. The ash content was positively correlated with P (r = 0.868, p&lt;0.05), Zn (r = 0.610, p&lt;0.05) and negatively correlated with energy (r = -0.704, p&lt;0.05). The locations of mushrooms were clustered into three main groups based on components by multivariate pattern recognition. Most variables had a strong association with Volvariella volvacea. The wide disparity in the constituents of species from different locations can make it possible for consumers to choose based on interest and nutrient content

Mycotoxin profiles of solar tent-dried and open sun-dried plantain chips

Published online: 10 Jul 2020Plantain is a popular dietary staple in Central and West African countries due to its versatility and excellent nutritional value. Mature unripe plantain finger is usually processed into dried chips by processors using open sun-drying method to reduce the moisture content and extends its shelf life, but without controlling the unit operations that affect product quality. Thus, this study aimed at assessing the mycotoxin profile of solar tent-dried and open sun-dried plantain chips in Nigeria. Fifty (50) dried plantain chips [10 samples produced from the solar tent-dried, 10 samples from open sun dried, and 30 samples from local processors (9 from Akure South and 21 from Idanre Local Governments)] were analyzed for constituent mycotoxins using Liquid Chromatography Tandem-Mass Spectrometry (LC-MS/MS). The result reveals that all the regulated mycotoxins (Aflatoxin B1, B2, G1, G2, Ochratoxin A, Fumonisin B1, Fumonisin B2, Zearalenone, T-2 Toxin, HT-2 Toxin and, Deoxynivalenol) were below the detectable limits in the dried plantain chips. Aflatoxin B1 and G1, which were considered as the most regulated mycotoxin, were below the limits of detection (0.16–0.22 μg/kg) in all the samples. Only 23 analytes were detected at concentrations higher than their respective limits of detection (LOD) in 2% or more of the 50 dried plantain chips investigated, with reference to the prevalence of the non-regulated mycotoxins. Thus, all regulated mycotoxins produced by Aspergillus, Penicillium and Fusarium as stipulated by the Commission of the European Union were found at concentrations which are toxicologically acceptable in many other crops, particularly in the solar tent-dried plantain chips compared to those from the open sun-dried and local processors. Therefore, the use of a solar tent in drying plantain chips and other agricultural products is encouraged for the safety of human consumption. The outcome of this study provides useful information regarding the possible safety of plantain chips in Nigeria

Pigments and colour characteristics: Influence of drying methods on Nigerian pepper (Capsicum frutescence)

Drying conditions such as temperature and duration leads to pepper modifications that can results into quality degradation. In this study matured red fresh Capsicum frutescens var. Baccatum (FB) and Capsicum frutescens var longum (FL) were dried using sun drying (SFB and SFL) and hot air cabinet drying (CFB and CFL) methods. Effects of drying was investigated on moisture content, water activity, carotenoid (capsorubin, violaxanthin, capsanthin, antheraxanthin and zeaxanthin) and colour characteristic (extractable, surface colour, non-enzymic browning index [NEBI]). Cabinet drying significantly (P < 0.05) reduced the moisture content and water activity to 7.7% and 0.41 in CFB and 7.5% and 0.42 in CFL compared to 8.5% and 0.45 in SFB and SFL by sun drying. Capsorubin was the most abundant carotenoid in both species (51 and 29%) and capsanthin (43 and 25%) in FB and FL. Extractable colour loss in FB was 31 and 26% due to sun and cabinet drying, while FL recorded 42 and 24%. The chromatic coordinates (a*, b × and L*) in the fresh C. frutescens var baccatum and C. frutescens var longum were significantly affected by the drying methods with values ranging from 23 to 28, 20–24 and 36–41 in the dried peppers. The highest NEBI values of 113 and 123 were recorded for the C. frutescens var baccatum while the lowest colour difference was recorded in C. frutescens var longum. Cabinet drying method provided higher NEBI with CFB having the highest values indicating that cabinet drying may be considered a better drying alternative for dehydration of red pepper due to better colour retention of the dried products

Effect of steam cooking and storage time on the formation of resistant starch and functional properties of cassava starch

In this study, resistant starch (RS), type 3, was prepared by debranching, steam cooking and storage of cassava native starch obtained from two Nigeria varieties (TMS 30572 and 98/0581). The native starch samples were debranched with isoamylase enzyme, steam cooked both at atmospheric and high pressure (15 psi) and stored under refrigeration (5–7°C) and freezing condition (−18°C) for 48 h. The effects of these processing conditions on the formation of RS were determined. The debranching process increased the resistant starch contents of the cassava starch to about 70% over the undebranched samples. The RS contents from the steam cooking process ranged between 5.99 and 19.55 g/100 g. The highest value was obtained in TMS 30572 debranched and steam cooked at atmospheric pressure while the least RS was obtained from TMS 98/0581 undebranched but steam cooked at atmospheric pressure. The RS contents increased with increase in storage time with refrigeration having a higher resistant starch contents compared with freezing. Formation of RS decreased the Swelling Power, Water Absorption Index and Water Solubility Index of the Starch while the Syneresis Value increased. This study showed that cassava starch is suitable for isoamylase debranching, and RS formation

Variation in pasting and functional properties of flours and starches from water yam (Dioscorea alata)

This study was carried out in order to compare pasting behavior and functional characteristics of flours and starches from ten varieties of water yam (D. alata). Differences were established among the arieties in the functional and physical properties of the starches and flours, including swelling power, solubility index, and water absorption capacity. The swelling power of the water yam flour and starch put them in the category of highly restricted swelling starch. This characteristic is desirable for the manufacture of value-added products such as noodles and composite blends with cereals. The uses of starch from improved yam varieties to impart viscosity to locally processed foods have remarkable potential in Africa.Cette étude a été effectuée afin de comparer le comportement de coller et les caractéristiques fonctionnelles des farines et des amidons de dix variétés d’igname (D. alata). Des différences ont été établies parmi les variétés examinées dans les propriétés fonctionnelles et physiques de leurs amidons et leurs farines, y compris le pouvoir de gonflement, l’indice de solubilité et la capacité d’absorption d’eau. La pouvoir de gonflement de la farine de l’eau yam et l’amidon les a mis dans la catégorie d’amidon d’un gonflement restreint très élevée. Cette caractéristique est un atout pour la fabrication des produits à valeur ajoutée tels que les nouilles et les composites à base de mélange de céréales. Les utilisations de l’amidon obtenu de variétés améliorées d’igname peuvent donner la viscosité aux nourritures localement transformées auront le potentiel immense en Afrique