Effect of Sodium Acid Pyrophosphate and/or Potassium Sorbate on Staphylococcus aureus FRI-100 Growth and Toxin Production

The effect of food-grade sodium acid pyrophosphate (SAPP) alone or in combination with potassium sorbate (PS) on growth and toxin production by an enterotoxin A producing strain of Staphylococcus aureus was investigated. Growth of cultures was monitored by absorbancy readings (640 nm) at 5-hr intervals. Toxin production was determined by an Enzyme Linked Immunosorbent Assay (ELISA). SAPP (0.04%) in combination with PS (0.26%) was the most favorable treatment for inhibition of S. aureus growth. Concentration of toxin correlated with amount of growth in all treatments studied.     

Simultaneous HPLC Determination of 2,5-Dimethyl-4-hydroxy-3 (2H)-Furanone and Related Flavor Compounds in Strawberries

A rapid methodology (less than 90 min) is described for the qualitative and quantitative analysis of 2,5-dimethyl-4-hydroxy-3 (W)-furanone (furaneol), furaneol-β-glucoside, and 2,5-dimethyl-4-methoxy-3 (2H)-furanone (mesifurane) in strawberries. These compounds were resolved by HPLC with a RP C18 column, using acetate buffer and methanol as binary mobile phase and detection at 280 nm, and confirmed by GC-MS. The aqueous extraction procedure gave an average recovery of these compounds from strawberries > 90%, with detection limits: 0.14 furaneol, 0.05 furaneol-β-glucoside, and 0.36 μg/rnL mesifurane.     

ANTAGONISTIC EFFECT OF CPTA AND FAR-RED LIGHT ON THE CAROTENOGENESIS IN LUTESCENT TOMATOES1

Yellow lutescent tomatoes normally devoid of lycopene can be induced to produce this red pigment when treated with bioregulators such as CPTA, (2-(4-chlorophenylthio)-triethylamine hydrochloride). Red light and CPTA combination stimulated the accumulation of 225 μg/g of lycopene in mature white lutescent tomatoes after a 12-day ripening period. Tomatoes treated with CPTA but ripened in the dark produced 67 μg/g of lycopene. Far-red light treatment of the CPTA treated tomatoes produced only 25 μg/g of lycopene. Analysis of other carotenoids showed a similar trend indicating a quantitative but not a qualitative change in carotenogenesis in lutescent tomatoes as affected by light and by bioregulators. The antagonistic effect of far-red light toward CPTA suggested that the two effectors might work at the same reactive site in tomato cells.     

Reduction of chilling injury in ripe Alphonso mango fruit in cold storage by temperature conditioning

The influence of ripening temperature and cold conditioning of pre-climacteric fruits on the incidence of chilling injury (CI) in ripe mango fruits cv. Alphonso during refrigerated storage was investigated. Fruits previously held and ripened at tropical ambient temperature (AT, 27–34°C) developed CI (skin staining or browning) when ripe fruits were subsequently stored at 5, 10, or 15°C for shelf-life extension. Fruits held and ripened at 20°C1°C, RH 85–90% showed little evidence of CI when subsequently stored at 5 or 10°C up to 14 days. Chilling injury in ripe mangoes was also avoided by holding pre-climacteric fruits for a minimum period of 30 days at 10°C and then ripening them at 27–34°C. The quality of the ripe mangoes remained good during cold storage for 7 days and were acceptable until 10–14 days with minimal changes in texture, flesh colour, carotenoids, total soluble solids, titratable acids and ascorbic acid. Shelf-life of ripe mangoes can thus be extended under refrigeration by pre-storage conditioning.     

Form as Diagram of Forces: The Equiangular Spiral in the Work of Pier Luigi Nervi

The relationships between form, performance, and construction are uniquely demonstrated in the long-span works of Pier Luigi Nervi. The balance of these forces led in Nervi's case to a series of works that take the form of the equiangular spiral, a bizarre geometrical phenomenon that appears regularly in the natural world. The affinities between Nervi's work and the spiral's natural occurrences can be explained via D'Arcy Thompson's On Growth and Form , suggesting that this familiar book on biological morphology be seen by architects in a new and more thorough light.