JWSS - Journal of Water and Soil Science

---

In spite of different reports about the inheritance of cotyledon colour in lentil, the precise nature of this phenomenon is unknown. In a comprehensive study, conducted in 1993-96 on inheritance of morphological markers in lentil, two types of green colour, light green and dark-green lentils, were distinguished for the first time. The dark-green showed monogenic and the light-green showed digenic inheritance. To explain this, involvement of three genes, Dg, Y and B in the inheritance of cotyledon colour were considered. At the dominant state of gene Dg, the genes Y and B produce yellow and brown pigments, respectively. At the recessive state (dg dg), no pigment will be produced and the dark-green colour will appear. If gene Dg acts normally (dominant state), but both genes Y and B are at recessive state (Dg-yybb), again no pigment will be produced and cotyledons will be of light-green colour.

---

Recent restrictions on the use of artificial food colours have prompted extensive research on natural pigments as suitable substitutes. The red beet Beta vulgaris L. has been found as a suitable source of natural red pigment since beet powder and concentrates can conveniently be used in food products. In this research, hot and cold extractions of randomly selected red beets were used after preparation and blanching. The extracts were filtered and passed through a column of Amberlite XAD-7 resins after adjusting the pH to 2.5. The adsorbed colour compounds were extracted from the resins by eluting the column with acidified alcohol. The solvent was removed by vacuum rotary evaporator and solid colour was obtained, using a freeze dryer.

Physicochemical properties of the solid colour were determined by measuring ash and sugar contents of the solid colour. Also, its purity and stability were investigated under different conditions.

The amount of ash and sugar were negligible. The highest stability was observed at a pH value of 5 under cold and dark storage conditions. The purity of the solid colour was determined by scanning in the range of visible wavelengths and preparative TLC. The result showed that purity of the colour as a hundred percent betacyanins. The yield of production was calculated as 2.7 g powder per kilogram of beet. The colour was used in producing ice cream and frozen sherbets, which showed to be a suitable replacement for artificial colour carmoisine. Also the production cost of the colour was as low as less than 0.1 percent of that of ice cream or frozen sherbets.

---

Molasses are produced in large amounts by sugar cane and sugar beet factories every year. However, they are considered as the waste product of the crystallization plants. Thus, although they contain significant amounts of materials with deep black colour which can be separated as food colour, molasses are very cheap and feasible to be used for this purpose. Aliquots of diluted molasses, after adjusting the pH, were passed through the column followed by extraction with acidified alcohol. The highest yield of extraction (76.3%) was obtained by using diluted molasses (10° BX) and 150 ml of Amberlite resins. The solvent was removed and the solid colour was obtained by evaporating the water using a freeze drying system.

 The colour was characterized by determining its solubility, amount of ash, and sugar content and its colouring ability. Also, the stability of the colour under different conditions of acidic pH, temperature, and visible light was investigated. In addition, the colour values of the colour solution were measured by Hunter lab system.

The colour was compared with the imported caramel which is used in the black soft drinks of Zam Zam. Both had almost the same values of λ_max. Also, their sensitivities to pH changes were similar. Samples of soft drinks made by using the prepared colour were compared with those made by caramel under different conditions of storage such as temperature and light. On the whole, the colour was found to be a very suitable replacement for caramel in the production of black soft drinks.

 Also the colour was used as partial replacement for cocoa powder in making chocolate milk. The taste panel showed that cocoa powder can be replaced by the colour powder by 20% with almost no detectable differences. The caramel from molasses is safe and can be used as a food colour. The cost of production was estimated at about 10 Rials per gram of caramel. Thus, from an economical point of view, industrial production of caramel from molasses is profitable.

---

Flax (Linum usitatissimum L.), an oilseed crop, is widely adapted and grown in many regions of the world. Oil from regular flaxseed is used as an industrial drying oil because of the high level of linolenic acid (>50 %). However, the oils from new mutant genotypes of flax with a very low linolenic acid concentration (<2 %) are edible. Yellow seed colour can be used as a visual marker to distinguish edible-oil genotypes of flax from those of industrial type that are usually brown-seeded. In this study, different lines of flax with two seed colours (yellow and brown) in combination with two levels of linolenic acid (high and low) were evaluated in a randomized complete block design for agronomic traits, especially seed yield and its components. The results indicated that lines with high linolenic acid concentration had significantly higher seed yield than those with low linolenic acid. However, other characteristics including those of seed yield components were not siginficantly affected by linolenic acid concentration. Seed colour had a significant effect on number of seedling/m², basal branches, capsules per plant and seed yield per plant. Although seedling emergence was lower in yellow-seeded lines, they had more basal branches, capsules per plant and seed yield per plant. Higher seed yield per plant in yellow-seeded lines can be attributed to higher number of capsules per plant as a result of lower seedling emergence and plant density. Seed yield was not significantly different between brown and yellow-seeded lines. Thus, the effect of lower plant density in yellow-seeded lines was compensated by their higher basal branches and number of capsules per plant.