White Carrots Research Articles

Carotenoid profiles and consumer sensory evaluation of specialty carrots (Daucus carota, L.) of various colors.

Five different colored carrots were analyzed for their carotenoid profile and underwent sensory evaluation to determine consumer acceptance (n = 96). Four major carotenoids were identified and quantified by use of HPLC methods. High beta-carotene orange carrots were found to contain the greatest concentration of total carotenoids. Except for the white, all the carrots are a significant source of bioavailable carotenoids. Sensory evaluation showed the high beta-carotene orange and white carrots to be favored over the yellow, red, and purple carrots in both blind and nonblind treatments (P < 0.01). However, all the carrots were well accepted by the consumer panel. With this information, carrot growers should be encouraged to cultivate specialty carrots to provide sources of both vitamin A precursors and phytochemicals.

Three under-utilised sources of starch from the Andean region in Ecuador. Part II. Rheological characterisation

The dynamic rheological behaviour of Arracacha xanthorriza (white carrot), Canna edulis (achira) and Oxalis tuberosa (oca) starch gels were studied in strain-sweep mode. The starch was diluted with water to cover particle volume fractions of 1–3. The starch suspensions were heated at 89 °C for 30 min, and their swelling power and amylose leaching were measured. C. edulis showed the highest swelling power and particle rigidity (the elastic modulus, G′, of a starch gel at a particle volume fraction of 1 is defined as rigidity), forming stronger gels than O. tuberosa and A. xanthorriza. Storage of the three starch gels at 4 °C showed that A. xanthorriza formed gels which were stable in G′ and phase angle for three days of storage. C. edulis and O. tuberosa gels kept at the same refrigeration conditions showed a high increase in G′ during the first day of storage. A decrease in pH from 6.5 to 4.0 produced a loss of structure in the three starch gels, as was showed by the reduction of G′. Storage at freezing temperature (−20 °C) produced higher changes in G′ than refrigeration conditions. There was a rapid formation of an elastic structure in C. edulis and O. tuberosa starch gels on the first day of storage in both refrigeration and freezing conditions.

The development of the original European carrot material

1. European carrot improvement began with material imported from the Arab countries. It consisted of a purple type, called “red” by authors before about 1700, and a yellow type growing largely above the ground. 2. The purple carrot played a role in France during the 14th–17th centuries, in the Netherlands during the 15th–18th centuries, and in Germany during the 18th and possibly the 19th centuries. At first the purple carrot probably was the main type grown, later its use became very limited. 3. The yellow carrot became more generally used than the purple. It gradually spread throughout Europe and probably started superseding the purple in the 16th century. 4. The white and the orange carrots were probably selected from the yellow. 5. During the 17th and 18th centuries the white carrots were used in the French kitchen. In other countries they never became as popular as in France. 6. The first orange coloured garden carrots were produced in the Netherlands. Late Horn and Half long Horn probably were developed in the 17th century, whereas Short Horn probably was produced in the 18th century. It is possible that Long Orange types fit for kitchen use were produced in Holland during the 17th century by selection from the long yellow carrot, possibly after crossing with an unpalatable but more intensely coloured red-orange type. The orange Brunsvie appeared in Germany between 1684 and 1740. Originally it had the character of a forage carrot.

The effect of the accessory substances of plant tissue upon growth of bacteria

The study of the properties of blood upon which depends the ability of the so-called hemoglobinophilic bacilli to grow in this medium, has shown that these properties are related to at least two factors which can be separately studied. Further studies have shown that both of these factors are present in plant tissue, (potato and banana), and that sterile unheated vegetable tissue can replace blood in the cultivation of B. influenzce. These observations have now been extended; yellow and white turnip, carrot, beet, parsnip, and sweet potato, when added to fluid media have been found to possess the same growth stimulating action as white potato.It has been found that these vegetable tissues not only permit the cultivation of the so-called hemoglobinophilic organisms, but that they also greatly favor the growth of other entirely unrelated organisms. For instance, in the case of pneumococcus, not only is there a marked acceleration of growth, but a seeding too minute to initiate growth in plain broth alone, w...