Supercritical CO(2) and subcritical propane extraction of pungent paprika and quantification of carotenoids, tocopherols, and capsaicinoids.

Ground paprika (Capsicum annuum L.) was extracted with supercritical carbon dioxide (SC-CO(2)) and subcritical propane at different conditions of pressure and temperature to estimate the yield and variation in carotenoid, tocopherol, and capsaicinoid contents and composition. The yield of paprika extract was found to be affected by the extraction conditions with SC-CO(2) but fairly constant at different conditions with subcritical propane. The maximum yields of oleoresin were 7.9 and 8.1% of ground paprika by SC-CO(2) and subcritical propane, respectively. The quantitative distribution of carotenoids, tocopherols, and capsaicinoids between paprika extract and powder was influenced by extraction conditions. SC-CO(2) was inefficient in the extraction of diesters of xanthophylls even at 400 bar and 55 degrees C, whereas tocopherols and capsaicinoids were easy to extract at these conditions. Under mild conditions subcritical propane was superior to SC-CO(2) in the extraction of carotenoids and tocopherols but less efficient in the extraction of capsaicinoids.

Change in carotenoids and antioxidant vitamins in tomato as a function of varietal and technological factors.

The change in the carotenoid and bioantioxidant content of tomato as a function of varietal and technological factors was investigated in the present work. No great differences were found between cultivars for fresh consumption (salad tomatoes) and those for processing in ascorbic acid content. The concentration of ascorbic acid ranged between 14.6 and 21.7 mg/100 g fresh weight of ripe tomato fruit. Processing cultivars contained higher amounts of tocopherols, particularly alpha-tocopherol than tomatoes for fresh consumption. Significant differences could be obtained between the examined varieties with regard to carotenoid concentration. The different tomatoes varied not only in the total carotenoid content but also in the qualitative distribution of some pigments such as lycopene, beta-carotene and lutein. During heat-based processing, ascorbic acid, tocopherols, and carotenoids showed different role and response. Ascorbic acid, alpha-tocopherol quinone, and beta-carotene were the most susceptible components toward thermal degradation.

Lipoxygenase-catalysed degradation of carotenoids from tomato in the presence of antioxidant vitamins.

Carotenoid extract from ripe tomato fruit was subjected to a lipoxygenase-catalysed co-oxidation in the presence of vitamin C and vitamin E at different concentrations. Relative retention (%) of major carotenoids by the experimental mixture was used as an index of their degradation and interaction with the antioxidants. Oxidation-prevention activity of each antioxidant against pigment co-oxidation as impacted by their molar concentration was studied. beta-Carotene was found to be the most sensitive pigment, followed by lycoxanthin and lycopene. Ascorbic acid when added in the range of 0-1.8 mM interacted with the different carotenoids by different modes. Evidence was given on regeneration, by ascorbic acid, of lycopene during the course of co-oxidation. The concentration required for alpha-tocopherol acetate to exhibit antioxidative effect was 10 times higher than that of ascorbic acid. beta-Carotene was prevented, by alpha-tocopherol acetate, faster than lycoxanthin and lycopene. The latter carotenoids differed substantially in their interaction with the lipophilic antioxidant at only the lowest concentration (0.3 mM). It was established that under the given conditions there is no synergism between vitamin C and vitamin E that improves their oxidation prevention against co-oxidation of carotenoids. Moreover, the combined use of antioxidants caused more oxidative degradation of beta-carotene.

Change in the carotenoid and antioxidant content of spice red pepper (paprika) as a function of ripening and some technological factors.

A study was conducted to investigate the change in quality attributes of red pepper (paprika) (Capsicum annuum L. var. Km-622) as a function of ripening and some technological factors. Of quality attributes, carotenoids and bioantioxidants (ascorbic acid and tocopherols) have been studied. It was found that the dynamics of fruit ripening with regard to carotenoids and bioantioxidants was influenced to a considerable extent by weather conditions of the production season. A rainy and cool season yielded fruits with more beta-carotene but less diesters of red xanthophylls as compared to those produced in a relatively dry and warm season. The ripening stage at harvest was found to affect the quality of paprika. Harvest at unripe stages (color break or faint red) resulted in a high accumulation of dehydroascorbic acid in the overripe fruits, whereas de novo biosynthesis of carotenoids and tocopherols was partially retarded. Application of pre-drying centrifugation resulted in a marked loss of ascorbic acid, and as a consequence, carotenoid stability was impaired during the storage of ground paprika. Sugar caramelization caused dry pods and ground paprika to retain more pigments and tocopherol as compared to those from control or centrifuged red pepper samples. During the storage of ground paprika, color stability was improved by grinding the seeds with the pericarp.

Overview of food packaging research in Hungary.

In the last 15 years, increasing demands for improvement in food quality, and for increased food choice have grown in Hungary. To meet these new requirements, packaging is of decisive importance. Considerable developments have been achieved as a result of wide-ranging R&D activities. A review compiled by the author is presented of the actual situation regarding Hungarian food packaging, covering the main domestic institutions for R&D activities dealing with packaging materials and methods, together with a discussion of trends and results.

The effect of methicillin on the fatty acid composition of total polar lipid in methicillin resistant Staphylococcus aureus.

The effect of two concentrations of methicillin on the fatty acid (FA) distribution in intracellular total polar lipid (TPL) of the log-phase cultures of a methicillin resistant Staphylococcus aureus strain No. 5814R was studied during a period of 2 h. Half the MIC of methicillin (= 1000 micrograms/ml) caused 18.6% increase in branched-FAs and a same decrease in straight-FAs, while one MIC (= 2000 micrograms/ml) of the drug induced a moderate change in those of TPL. The ratio of branched-FAs to straight-FAs increased from 1.24 to 1.56 in the presence of 1/2 x MIC of methicillin and reduced from 1.24 to 0.87 in the presence of 1 X MIC of the antibiotic. In TPL of the control cultures it gradually decreased from 1.24 to 0.77. It is concluded that under the effect of methicillin, FA composition of TPL in methicillin resistant cocci does not change as dramatically as in methicillin sensitive ones indicating lipid synthesis in methicillin resistant S. aureus to be less sensitive to the action of methicillin than in methicillin susceptible strains. This may contribute to the resistance against the lytic effect of the drug. Membrane lipid properties seem to be involved in the mechanisms of methicillin resistance.

In vitro scavenger effect of dihydroquinoline type derivatives in different free radical generating systems.

The non-toxic and water soluble dihydroquinoline type antioxidants: CH 402 (Na-2,2-dimethyl-1,2-dihydroquinoline-4-yl methane sulphonate) and MTDQ-DA (6,6-methylene bis 2,2-dimethyl-4-methane sulphonic acid: Na-1,2-dihydroquinoline) were studied in various in vitro tests in which oxygen free radicals were generated. Both compounds were shown to scavenge superoxide radical anions O2- produced in aqueous solution by pulse radiolysis with rate constants k (O2- + MTDQ-DA) = 4.10(8) dm3 mol-1 s-1 and k (O2- + CH 402) = 1.5.10(7) dm3 mol-1 s-1. CH 402 and MTDQ-DA reduced the H2O2 produced in the glucose-glucose oxidase reaction, which was detected by the luminol + hemin reaction with a chemiluminometric method. The dihydroquinoline type substrates inhibited the NADPH-induced and Fe3+ - stimulated lipid peroxidation and the ascorbic acid-induced non-enzymatic peroxidation pathways in microsomal fractions of rat and mouse liver.

Effect of methicillin on the fatty acid composition of phospholipids in methicillin sensitive Staphylococcus aureus.

The effect of two concentrations of methicillin on the distribution of fatty acid (FA) in the individual phospholipids of the middle-log phase cultures of Staphylococcus aureus 5814S sensitive to methicillin was studied during a period of 2 h. In the presence of 1/2 X minimum inhibitory concentration (MIC) of methicillin (= 1 microgram/ml) the ratio of unsaturated fatty acid (UFA) + branched fatty acid (BFA) to saturated fatty acid (SFA) in the phosphatidic acid (PA) and in the C55-isoprenylphosphate (C55-IP) became significantly higher due mainly to the accumulation of n-C12 : 3, ai-C17 : 0, and ai-C19 : 0, and to the fall of n-C14 : 0, n-C16 : 0, and n-C20 : 0 in the PA, and to the 3-fold increase in n-C12 : 3 and a 2-fold decrease in the SFAs of the C55-IP. In contrast, the ratio of UFA + BFA to SFA was smaller in the phosphatidylglycerol (PG) and lysylphosphatidylglycerol (LPG) than that of the control. The reduction was attributed to a loss of ai-C15 : 0 and a gain of n-C20 : 0 in the PG, and to the decrease in ai-C17 : 0 and to the increase in n-C20 : 0 in the LPG. On the whole, the fluidity of the membrane phospholipids decreased. In the presence of 1 X MIC of methicillin (= 2 micrograms/ml) the ratio of UFA + BFA to SFA became higher in the PA due mainly to the prevention of the release of n-C18 : 1. In all the other phospholipids the ratio of UFA + BFA to SFA was smaller than in the control of the same age. The decrease in the ratios ranged in the order of C55-IP, PG, diphosphatidylglycerol (DPG) and LPG. The changes were attributed to the decrease in the proportion of n-C12 : 3 and ai-C15 : 0 or ai-C17, and to the increase in n-C20 : 0, except DPG. Thus the membranes in methicillin treated cocci were significantly less fluid than in the controls.