A study of some important vitamins and antioxidants in a blackcurrant jam with low sugar content and without additives.

Blackcurrant (Ribes nigrum) jam was manufactured with the aim of producing a jam with a low sugar content, and without any additives. Four temperatures were investigated, namely 60 degrees C, 76 degrees C, 92 degrees C and 97 degrees C. Processing time varied between 1-20 min. After processing, the highest content of ascorbic acid was found in the jam processed at 97 degrees C for 1 min, which contained 63.3 +/- 2.6 mg ascorbic acid/100 g jam. At all combinations investigated more than 60% of the original amount of ascorbic acid was retained after manufacturing and packaging. The jam made at 92 degrees C was stored in a shelf-life study for 13 months. The jam was then stored at 8 degrees C, ambient temperature and at 37 degrees C. At ambient temperature the jam was stored both in dark and in daylight, at 8 degrees C and at 37 degrees C the jam was stored in dark. After 13 months of storage, at 8 degrees C, 60% of the amount of ascorbic acid and 29% of the amount of anthocyanins were retained. In the jam stored at higher temperatures less of both was retained. The beta-carotene in the jam was found to be stable throughout the whole shelf-life study. Exposure to light did not have any effect on any of the components studied. The degradation of anthocyanins was best described by a second-order reaction and the activation energy was determined to be 90 kJ/mol. A jam of blackcurrant may be considered as a good source of vitamins and antioxidants after one year, if certain precautions concerning manufacture and storage conditions are taken.

Changes in plasma insulin, enterostatin, and lipoprotein levels during an energy-restricted dietary regimen including a new oat-based liquid food.

The changes in plasma insulin, enterostatin, lipid, and glucose levels during weight reduction were studied in 32 subjects having a body mass index of 25-35. The 31 subjects who completed the study followed for 23 weeks an energy-restricted dietary regimen which included a new oat-based soup as the main meal once or twice daily. The intake of energy decreased from 8.9 to 6.2 MJ/day from 0 to 22 weeks, the energy percentage from fat decreased from 35 to 30%, and the intake of dietary fiber increased from 21 to 25 g/10 MJ. The body weight decreased from 83 to 78 kg after 6 weeks and to 77 kg after 23 weeks. Plasma glucose had decreased significantly from 5.4 to 5.2 mmol/l, and plasma insulin from 122 to 98 pmol/l after 23 weeks. In contrast, the plasma enterostatin concentration did not vary significantly over five sampling times, the mean values ranging from 25 to 30 nmol/l. Plasma cholesterol declined from 5.6 to 5.2 mmol/l, low-density lipoprotein cholesterol from 3.8 to 3.3, and plasma triglycerides from 1.5 to 1.3 mmol/l from 0 to 23 weeks. High-density lipoprotein cholesterol increased from 1.1 to 1.3 mmol/l. It is concluded that an energy-restricted regimen leading to lower plasma insulin, triglyceride, and low-density lipoprotein cholesterol levels did not significantly affect the plasma enterostatin concentration in overweight subjects. A new oat-based liquid food as a part of the dietary regimen was well tolerated.