Total antioxidant capacity of meat and meat products consumed in a reference ‘Spanish standard diet’

The antioxidant capacity (AC) of meat, meat products and the comparison with fish, vegetable products, milk and a balanced and healthy diet was determined using the ORACFL assay. The hydrophilic ORACFL (H‐ORACFL) of hake and sardine was 596 ± 133 and 641 ± 128 μmol Trolox Equivalents (TE) per 100 g, respectively. The highest H‐ORACFL value was found in cured meat samples, where Iberian cured ham (4890 ± 443 μmol TE per 100 g), whereas the lowest level of 797 ± 68 μmol TE per 100 g was found in Frankfurt sausages. Products like mortadela with olives, sobrasada and salami showed intermediate values ranging between 1107 ± 123 μmol TE per 100 g and 1011 ± 63 μmol TE per 100 g. Iberian cured ham presents the higher AC of all meat products studied, and this value being higher than that provided by red wine (3135 ± 312 μmol TE per 100 g). The AC of orange juice was lower than meat products, with the exception of Frankfurt sausages. Finally, the estimated total antioxidant capacity (TAC) of the reference standard diet was 29 006 μmol TE per intake whole diet per day, and meat representing 10.51% per intake per day of the TAC of the whole diet.     

An Objective Dry Pea ‘Colour’ Scoring System for Commercial and Plant Breeding Applications

For human consumption, colour of dry peas is an important quality criterion, presently assessed subjectively. Samples which are dark and even in colour are preferred to those which are bleached and variable. The capacity of image analysis methods to provide an objective colour scoring system was investigated, and useful predictive relationships were found between subjective rankings for colour allotted to members of a large set of training samples, and ranking for median optical density, optical density proportional range and median seed size. Training samples were drawn at random from the pea sample population, and were not evenly distributed, so spacings between rankings were corrected by reference to the variance of the mean ranking for a sample. This correction allowed the predictive variables to explain 64% of the observed variation in the corrected rank. When the required precision of a derived scoring system was set to ±1·0 score points, it was found that the set of training samples could be covered by 6·95 score points, so a scoring calibration equation was developed in which increasing colour loss caused a higher score. The darkest sample in the training set was arbitrarily chosen to have a score of 5, to allow for the possibility of intrinsically darker, less bleached samples. This scoring system is at least twice as precise as the current subjective approach, and can be applied using any image analysis system that can be calibrated against cheap, highly consistent, photographic standard grey cards. The performance of the system may be improved further if chrominance variation can be taken into account. © 1997 SCI.     

New vectors for combinatorial deletions in yeast chromosomes and for gap-repair cloning using ‘split-marker’ recombination

New tools are needed for speedy and systematic study of the numerous genes revealed by the sequence of the yeast genome. We have developed a novel transformation strategy, based on ‘split-marker’ recombination, which allows generation of chromosomal deletions and direct gene cloning. For this purpose, pairs of yeast vectors have been constructed which offer a number of advantages for large-scale applications such as one-step cloning of target sequence homologs and combinatorial use. Gene deletions or gap-repair clonings are obtained by cotransformation of yeast by a pair of recombinant plasmids. Gap-repair vectors are based on the URA3 marker. Deletion vectors include the URA3, LYS2 and kanMX selection markers flanked by I-SceI sites, which allow their subsequent elimination from the transformant without the need for counter-selection. The application of the ‘split-marker’ vectors to the analysis of a few open reading frames of chromosome XI is described.