Starch-based edible films of improved cassava varieties Yavo and TMS reinforced with microcrystalline cellulose

The results of a recent study on starch-based films of improved cassava varieties show that these films have poor barrier properties and lower mechanical strength. Thus, for some applications, improving their resistance to breaking forces is a key factor in making their use possible and sustainable. In this study, to the starch of two improved varieties of cassava (Yavo and TMS), combined with peanut oil, soybean lecithin, glycerol was added microcrystalline cellulose (MCC) at 0, 7, 15 and 30 %. The addition of microcrystalline cellulose has resulted in an increase in the opacity (223.91 nm.UA to 425.33 nm.UA for Yavo and 251.42 nm.UA to 434.51 nm.UA for TMS), tensile strength (7.15 MPa–10.99 MPa for Yavo and 7.77 MPa–13.18 MPa for TMS), and Young's modulus (331.29 MPa–1351.08 for Yavo and 343.79 MPa–1476.08 MPa for TMS) of films. However, MCC induced a decrease in moisture content (15.99 %–11.43 % for Yavo and 14.24 %–10.66 % for TMS), water solubility (24.84 %–20.61 % for Yavo and 24.15 %–19.36 % for TMS), elongation at break (22.75 %–1.31 % for Yavo and 21.25 %–1.19 % for TMS) and water vapour permeability (WVP) (1.98 * 10-11 to 1.39 * 10-11 g Pa-1. s-1.m1 for Yavo and 1.93 * 10-11 to 1.29 * 10-11 g Pa-1. s-1.m1). The MCC has also produced yellowish-coloured films. MCC has been shown to be effective in improving starch-based films of improved cassava varieties Yavo and TMS. These two varieties can be used in combination with MCC to produce food packaging

Effect of glycerol, peanut oil and soybean lecithin contents on the properties of biodegradable film of improved cassava starches from Côte d’Ivoire

peer reviewedEdible films have been successfully used in the food packaging industry for several decades. Today natural polysaccharides, including cassava starch, are increasingly being used in the production of such biodegradable edible films and food packaging. In Côte d'Ivoire, there are improved cassava varieties whose starches have not yet been tested in the production of biodegradable films. In this study, the optical and mechanical properties and the water solubility of starchbased composite films of four improved cassava varieties with added glycerol, peanut oil and soy lecithin were determined. Starch was obtained by cold water extraction from native cassava from the varieties Bocou 1, Bocou 2, Yavo and TMS. Films preparation was made bycasting method with cassava, glycerol (25-30 %), peanut oil (5-10%) and soybean lecithin (0-5 %). Increasing the glycerol content, increased L*color value and elongation at break and decreased a*, b*, colourdifference (ΔE* ab) and tensiles trength of the composite films. Also, increasing the oil content from 5 to 10%, increased the opacity, b*, ΔE*ab, water solubility, elongation at break but decreased L*, a* and tensiles trength. Similarly, increasing the soy lecithin content from 0 to 5%, increased the opacity, L*, b* and ΔE*ab, but decreased a*, of the starch-based composite films. The results suggest an ideal formulation of 4% starch/25% glycerol/5% oil/5% soy lecithin for a film with optimum mechanical properties with low solubility

Histological Study of the Polarity of Yam Tuber (Dioscorea spp.) at the Beginning of Tuberization

Yam, like most roots and tubers, has a tissue variation that is responsible for the difference in cooking observed during culinary preparations. In order to understand the origin of this variation, this study was conducted through optical microscope and SEM observation of the beginning of tuberization. The local variety named Kponan of Dioscorea cayenensis-rotundata was used. The days after the beginning of the tuberization, the protrusion of the stem base intensified and gives rise to the tuber. The histological study of the onset of tuberization revealed once again the existence of a longitudinal growth gradient whose point of growth is the apex and the sense of maturity of the distal part at the proximal end. The cells birth at the apex and differ a little more towards the middle part of the tuber. The apex is the driving zone for the tuber's lengthwise growth. The cambial cells ensure this growth in length and thickness of the tuber. The tuber's growth activity decreases from the distal part to the proximal one. The distal part contains more vacuolated cells thus rich in water and less starch than the middle and proximal parts. The cell wall is thin and less lignified. The cambium generates cells at the lower end of the apex. These very vacuolated cells differentiate and will form the median and proximal parts of the tuber. The distal part will remain immature compared to the other two parts. This could explain the low dry matter and the origin of rejection or elimination of the distal part during culinary operations