Search

In the present work, we study the use of near infra-red spectroscopy (NIRS) technology together with a remote reflectance fibre-optic probe for determination of the major components in bee pollen. The method allows immediate control of the bee pollen without prior sample treatment or destruction through direct application of the fibre-optic probe to the sample. The regression method employed was modified partial least squares (MPLS). The calibration results obtained using 45 samples of bee pollen allowed the measurement of protein, moisture, ash, reducing sugars, and pH with multiple correlation coefficients (RSQ) and prediction corrected standard errors (SEPC) of 0.91, 0.56% for protein, of 0.78 and 0.49% for moisture; 0.92 and 0.049% for ash; 0.81 and 1.32g of glucose/100g of bee pollen; 0.84 and 0.15 for pH, respectively. The prediction capacity of the pattern was checked by applying it to samples of unknown pollen in external validation.

Diacetyl and 2,3-pentanedione react with isoniazide in acidified solutions to give the corresponding hydrazones which, by reacting with a zirconium (IV) salt, form fluorescent complexes. Both reactions have been studied separately. Variables such as pH, heating time, and excess of reactives are discussed. The method may be used for the determination of these compounds in foods.