DIAPAUSE INDUCTION AND POST-DIAPAUSE EMERGENCE IN TRICHOGRAMMA MINUTUM RILEY (HYMENOPTERA: TRICHOGRAMMATIDAE): THE ROLE OF HOST SPECIES, TEMPERATURE, AND PHOTOPERIOD

1995 ◽  
Vol 127 (1) ◽  
pp. 103-110 ◽  
Author(s):  
J.E. Laing ◽  
J.E. Corrigan

AbstractTrichogramma minutum Riley entered diapause, in the prepupal stage, in eggs of Lambdina fiscellaria fiscellaria Guenée held at 15°C, 12L:12D, but failed to do so in eggs of Ephestia kuehniella (Zeller), Sitotroga cerealella (Olivier), or Choristoneura fumiferana (Clemens) held under these conditions. The parasitoids emerged without diapause from eggs of all host species held at 25°C, 16L:8D, indicating a role of temperature or photoperiod, or both, in the diapause of the parasitoids in eggs of L. fiscellaria held at 15°C, 12L:12D. Percentage emergence of parasitoids from eggs of L. fiscellaria was virtually the same (>80%) after passing the winter outdoors or after approximately 3 months at 2 °C in the laboratory as it was when reared indoors in this host at 25°C, 16L:8D. Emergence of T. minutum was very poor (<20%) after long-term, low-temperature storage in eggs of C. fumiferana, E. kuehniella, or S. cerealella. Apparently, T. minutum must parasitize diapause host eggs in order to enter diapause, and good survival after long-term low-temperature storage is possible only when T. minutum is in diapause. Trichogramma minutum will enter diapause in L. fiscellaria after 14 days at 15°C, 12L:12D, but the parasitoids need a period of storage at 2°C, 0L:24D for a high percentage of emergence to happen. Over 50% emergence was recorded for T. minutum, held for 300 days in eggs of L. fiscellaria.

Author(s):  
S. V. Kitaevskaya ◽  
O. A. Reshetnik

This work was aimed at investigating effects of low-temperature processing on the activity of proteolytic enzymes in various flour types. This study allowed an improved understanding of the mechanisms that change biotechnological processes in semi-finished dough products during low-temperature storage. The study of the effect of long-term low-temperature exposure on the activity of proteolytic enzymes in various flour types showed that this parameter depends on the medium pH, as well as on the flour type. During low-temperature storage, the activity of acid proteases tend to decrease by, on average, 10% in both traditional and non-traditional types of flour used for baking. The activity of weakly acidic and weakly alkaline proteases under the influence of low temperatures during storage depends on the flour type. At pH = 5.5, an increase in the duration of low-temperature exposure leads to a decrease in the proteolytic activity of spelt, wheat and buckwheat flour by, on average, 20, 12.5, and 18%, respectively. Conversely, this parameter increases in rye and oat flour by 12 and 28%, respectively. Under the influence of freezing and during low-temperature storage, the activity of weakly alkaline proteases in all studied flour types increases by 15.9%, except for buckwheat, the proteolytic activity of which decreases by 1.5–2 times during storage. It was established that proteolytic enzymes of corn flour exhibit the greatest resistance to long-term storage in a frozen form. Knowledge of the effect of low-temperature processing on the activity of proteolytic enzymes is important for predicting the rheological properties of semi-finished dough products and structural-mechanical and organoleptic characteristics of finished products. In addition, this knowledge facilitates the development of recipes and technological parameters for producing new bakery products based on frozen semi-finished products from traditional and non-traditional flour types.


2017 ◽  
Vol 1 (1) ◽  
pp. 8
Author(s):  
Gysberth Pattiruhu ◽  
Yohannes Aris Purwanto ◽  
Emmy Darmawanty

Mango (Mangifera indica L.) is perishable horticulture product. Commercially, mango fruits are harvested at the mature-green stage of development and are handled at low temperatures to facilitate shipping. However, long term low temperature storage of mature-green mango fruits is currently risky because of chilling injury (CI). The ojective of this study was to examine quality changes of mango during storage at 8 oC after heatshock treatment. Heatshock treatment consist of hot water treatment (HWT) at temperature of 55 oC in 3 and 10 minutes and intermittent warming (IW) at temperature 20 oC for 1 day after 2 and 3 days of low temperature storage. The result showed that HWT of 55 oC in 3 minutes could decrease of weight loss and maintain the quality and chemical content of mango during storage at low temperatures. While IW treatment after 2 and 3 days at low temperature storage in this study was not effective in reducing chilling injury and maintaining quality of mango.Keywords: chilling injury, hetshock treatment,low temperature storage, mango


Alloy Digest ◽  
1964 ◽  
Vol 13 (8) ◽  

Abstract USS 9% Nickel Steel was specifically developed for low-temperature storage vessels operating down to minus 320 F. It is recommended for cryogenic service. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as fracture toughness. Filing Code: SA-166. Producer or source: United States Steel Corporation.


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