Browsing by Subject "Canned"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Publication
    Embargo
    Effect of industrial processing on amino acid content of broccoli
    (Wiley, Society of Chemical Industry, 2001) Murcia Tomás, María Antonia; López Ayerra, Beatriz; Martínez Tomé, Magdalena; García Carmona, Francisco; Tecnología de Alimentos, Nutrición y Bromatología
    The levels of amino acids in broccoli stems and florets before and after various blanching times (in the case of freezing) and after bottling have been studied to elucidate to what extent nutrient quality is affected by industrial processing. The following amino acids (mg kg-1 fresh weight) were identified by ion exchange chromatography in raw broccoli florets: glutamine (1338), proline (732), asparagine (578), valine (310), arginine (296), isoleucine (204), threonine (169), leucine (166), phenylalanine (159), aspartic acid (140), lysine (127), alanine (122), tyrosine (105), S-methylcysteine (96), histidine (89), ornithine (59), glutamic acid (44), -y-aminobutyric acid (31), glycine (11) and serine (0.2). Raw stems contained the same amino acids but at lower levels (p < 0.05). The levels of all these amino acids fell during both industrial processes studied (bottling and freezing after blanching for 60, 90, 120 and 150 s), particularly in the frozen samples (losses of 50-70% in the florets and 20-50% in the stems). In summary, losses of broccoli amino acids were lower if blanching times were kept short. The optimal blanching time at 94 C for florets and stems intended for freezing was 90 s, and this did not result in any great loss of nutritional value related to amino acid content. Bottled florets had greater nutritional value than those frozen after being exposed to the longest blanching times (120 and 150 s).
  • Thumbnail Image
    Publication
    Restricted
    Effect of industrial processing on chlorophyll content of broccoli
    (Wiley, 2000-06-14) Murcia, María Antonia; López Ayerra, Beatriz; Martínez-Tomé, Magdalena; García Carmona, Francisco; Tecnología de Alimentos, Nutrición y Bromatología
    Chlorophylls a and b and pheophytins a and b were quantitaty determined in raw, frozen (after blanching for 60, 120 or 150s) and canned florets and stems of broccoli. The chlorophyll a and b contents were 0.11 and 0.043g/kg fresh weight respectively in raw florets and 0.036 and 0.018g/kg respectively in stems. About 37.8% and 61.1% losses were incurred during the freezing process in florets and stems respectively, and 98.5%after canning as a consequence of industrial processing. After different blanching times the losses of chlorophyll a in frozen florets varied between 17.7 and 66.4%, while the losses of chlorophyll b varied between 23.2 and 48.8%. In the losses ranged from 55.5 to 75% and from 50 to 88.9% for chlorophylls a and b respectively. These losses resulted in an increase in pheophytin a and b levels in both florets and stems.