SYNTHETIC HONEY PREPARATION BY YEAST CELLS AND IMMOBILIZED YEAST CELLS FROM SALIVARY GLANDS OF HONEY BEES
Yeast from the salivary glands of honey bees Apis mellifera and Apis cerana was isolated and used for preparation of synthetic honey. Free as well as immobilized yeast cells of these two species were studied for efficiency in preparation of synthetic honey from sucrose solution. The solutions exhibited lowered pH and increased level of fructose and total amino acids. The content of synthetic honey increased with increase in the time of incubation till 48 hours and decreased thereafter. The obtained solution possessed properties similar to the natural honey.
Invertase activity in honey
The invertase activity was determined for 499 honeys (27 multifloral and 472 unifloral from Arbutus, Carduus, Castanea, Citrus, Erica, Eucalyptus, Hedysarum, Helianthus, Rhododendron, Robinia, Rosmarinus, Taraxacum, Thymus, Tilia, fir honeydew and honeydew produced by Met- calfa pruinosa), in order to determine its variability and establish the range characteristic for each honey type. The results show that invertase activity varies considerably in the different honey types (from less than 0.5 to more than 30 IN). Robinia, Arbutus, Citrus, Erica and Rosmarinus have the lowest values (usually less than 10) and the two honeydew honeys the highest (more than 18). The diastase content of the samples was also measured, to compare the content of the two enzymes, and a certain correlation was observed (r = 0.835, P < 0.001). The IN/DN ratio ranges from less than 0.1 to more than 2. The possible role of invertase and IN/DN ratio in honey quality evaluation is discussed. © Inra/DIB/AGIB/Elsevier, Paris
Synergistic Effect of High Temperature and High pH on the Destruction of Salmonella enteritidis and Escherichia co1i O157:H7.
This study was undertaken to determine if high temperature and high pH interact synergistically to enhance the rate of destruction of two important gram-negative foodborne pathogens, Escherichia coli O157:H7 and Salmonella enteritidis . The rates of destruction in NaHCO3-NaOH buffers at pH 7.0, 10.0, and 11.0 were determined at 35, 40, 45, 50, 55, 60, and 65°C. Use of an improved heating protocol eliminated a "tailing effect" at longer exposure times. The present study demonstrated that the combination of high pH and high temperature resulted in a highly significant synergistic interaction (P > F = 0.0001), which caused rapid death of both E. coli O157:H7 and S. enteritidis . This "alka-therm" technology might be used commercially to destroy gram-negative foodborne pathogens on various raw agricultural commodities.