Tomatoes may have a great impact in the prevention of some types of cancer. This protective effect has been attributed to lycopene. The biosynthesis of lycopene is affected by environmental conditions. If the temperature of the fruits exceeds 30 • C, the synthesis of lycopene is inhibited. Strong direct radiation on fruits (∼2990 µmol m −2 s −1 for 1.5-4 h) is harmful. In 2002, we investigated the effect of temperature and photosynthetically active radiation (PAR) on lycopene content. Fruit samples were harvested three times during the growing phase. The average lycopene content of harvested fruits, picked on 18 June 2002, reached 64.9 mg kg −1 of fresh tomato. The fruits gathered on 25 June 2002 contained on average only 35.5 mg of lycopene per kilogram. The average lycopene content from the third harvest (on 9 July 2002) was 68.9 mg kg −1 . The values of PAR varied between 150 and 415 µmol m −2 s −1 , so they did not exceed the critical value. The average temperature preceding the second harvest was the highest (28-32 • C) and the maximum temperature ranged between 40 and 43 • C. This prolonged, extremely high temperature may have caused the low lycopene level in the second harvest. The lycopene content of six ripeness stages, from green to deep red stage, was measured in 2002 and 2003. The accumulation of lycopene accelerates from the pink stage and there is a high correlation (R 2 = 0.92) between lycopene content and colour values (a * /b * ). The higher the ratio of a * /b * , the higher was the lycopene content.

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Abstract:The nutritive value of the pumpkin seed products was evaluated. Isolation of protein eliminated 80% of the phytic acid and 100% of the tannic acid, trypsin inhibitor and flatulence factors. Ethanol treatment during the preparation of the protein concentrate reduced tannic acid by 78 YO and trypsin inhibitor by 21 YO, while it had no effect on the phytic acid content. Isoleucine and valine were the first limiting amino acids for meal and protein concentrate, while the sulphur-containing amino acids and valine were first limiting in pumpkin protein isolate-I and isolate-N, respectively. Pumpkin seed products had high levels of crude protein in the range 72G960 g kg-'. In-vitro protein digestibility and biological value were in the ranges 88-97 YO and 73-86 YO, respectively. Both meal and concentrate were rich in minerals (Ca, K, P, Mg, Fe and Zn) while isolates contain remarkable levels of sodium and copper. Pumpkin meal is a good source of the vitamin B group, while a large proportion of these vitamins is lost during the preparation of the protein concentrate and isolates.