Potatoes brown

Enzymatic polymerization of soluble lignin fragments (lignin oligomer) was demonstrated. In the polymerization catalyzed by HRP, or polyphenol oxidase (potato), brown precipitates were formed (286). The increase of the molecular weight was observed in the laccase-catalyzed treatment of the lignin oligomer (287). 

Caraway Seed. This spice is the dried ripe fmit of Carum carvi L. (UmbeUiferae). It is a biennial plant cultivated extensively in the Netherlands and Hungary, Denmark, Egypt, and North Africa. The seed is brown and hard, about 0.48 cm long, and is curved and tapered at the ends. It is perhaps the oldest condiment cultivated in Europe. The odor is pleasant and the flavor is aromatic, warm, and somewhat sharp (carvone). Caraway is used in dark bread, potatoes, sauerkraut, kuemmel Hqueurs, cheese, applesauce, and cookies. 

Optimum toxin production was found in a stirred, aerated culture medium consisting of potato infusion and sucrose after 3 to 5 days growth. The toxin was adsorbed on charcoal from the culture filtrate and eluted with chloroform. The red-brown residue remaining after evaporation showed little or no absorption in the carbonyl region of the infrared and only weak absorption in the ultraviolet. However, on mild treatment with acid, base, or heat two carbonyl peaks appeared at 1715 and 1685 cm.-1 in the infrared and at 266 mft in the ultraviolet (3). 

The minimum detectable level is estimated with the dinifroaniline signal-to-noise ratios (S/N). With fortification levels between 0.2 and 0.5mgkg the recovery of trifluralin from plant matrices is 70-99% with the LOD/LOQ being 0.005 mg kg according to the analytical method of the Ministry of the Environment, Japan. In multiresidue analysis by GC/NPD, the percent recoveries of pendimethalin from each crop with a fortification level of 0.25 mg kg were brown rice 70, potato 70, cabbage 80, letmce 89, carrot 84, cucumber 64, shiitake 74, apple 76, strawberry 99, and banana 99%. The LOD for each sample was 0.01 mg kg for pendimethalin. In residue analysis by GC/ECD, recoveries of the majority of dinifroaniline herbicides from fortified samples of carrot, melon, and tomato at fortification levels of 0.04—0.10 mg kg ranged from 79 to 92%. The LODs were benfluralin 0.001, pendimethalin 0.002 and trifluralin 0.001 mg kg for the GC/ECD method. ... 

Hajslova J, Schulzova V, Slanina P, Janne K, Hellenas KE and Andersson C (2005) Quality of organically and conventionally grown potatoes Four-year study of micronutrients, metals, secondary metabolites, enzymic browning and organoleptic properties . Food Additives and Contaminants, 22, 514—534. 

Brown CR, Edwards CG, Yang CP and Dean BB. 1993. Orange flesh trait in potato inheritance and carotenoid content. J Am Soc Hort Sci 118 145—150. 

Recovery Plan for Ralstonia solanacearum Race 3 Biovar 2 Causing Brown Rot of Potato,... 

Signs Causes warty outgrowths on all tissues other than the roots. Most frequently affected are the stems, stolons, and tubers. Outgrowths can be tan, green, or brown. Currently there is no control for this disease. Once introduced into a field, the entire crop may be rendered unmarketable. Moreover, the fungus is so persistent that potatoes cannot be grown again safely for many years. 

The nodules range in diameter from 20 pm to 15 cm, with most between 1 and 10 cm. As shown in Table 18.4, they are composed predominantly of manganese and iron oxides (about 20% each). They are generally dark brown and have the appearance of dirty, lumpy potatoes or hamburgers, with some being spherical and others more discoidal. 

Fig. 6. Spin-echo Image of diseased potato showing hollow heart (dark area) surrounded by brown tissue (bright area). Printed with permission, from Ref. 92.

Because concentrations of thorium in foods are very low, very few data exist. The thorium-232 content in fresh fruits, vegetables, and tea was determined (in pCi/g), and the values are listed in Table 5-1. Vegetables grown in an area of high natural activity in Brazil had the following concentrations of thorium (pg/g in dry sample) (Linsalata et al. 1987) brown beans, 0.011 potato, 0.0019 zucchini, 0.011 corn, 0.0022 carrot, 0.0074 and sweet potato, 0.0027. These authors did not observe rapid transport of thorium-232 from soil to the edible parts of the plants. 

Brown, C. R. (1993). Outcrossing rate in cultivated autotetraploid potato. Am. Potato J., 70, 725-734. 

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