CONTENT OF CARBOHYDRATES AND SPECIFIC ROTATION ANGLE OF HONEY

Abstract The main carbohydrates of honey are fructose, glucose, sucrose and maltose. Invertase hydrolyzes sucrose about fructose and glucose. Therefore low content of sucrose and high content of glucose and fructose in honey are parameters for characterization of honey quality. Several sorts of honey contain heightened content of maltose. Therefore it is possible to use this criteria for identification several honey sorts. Each carbohydrate has a specific angle of rotation of polarized light (specific rotation). It depends on relations and content of carbohydrates in honey. The aim of the present research was to establish the relationship between honey sorts and content of carbohydrates as well as specific rotation and possibilities of using these criteria (content of carbohydrates, specific rotation, and activity of invertase) for characterization of honey quality. Following parameters were determined with different physico -chemical methods: specific rotation -by method of polarimetry, content of sugars with high pressure liquid chromatography and activity of invertase -spectrophotometrically. The following results of honey analysis were obtained: the activity of invertase 4-30 (invertase number); content of carbohydrates (sucrose 0.5-3.0%, glucose 30-38%, fructose 35-42%, and maltose 1-6%); specific rotation 20 ] [ D α at -16° to -5°. The obtained results indicated that content of carbohydrates partially dependent on honey sorts. Content of sucrose depends from invertase activity in honey. Invertase is good parameter for honey characterization. Specific angle of rotation of polarized light is not available for identification of honey sorts

FOODBALT 2011 BIOACTIVE COMPOUNDS IN LATVIAN WILD EDIBLE MUSHROOM BOLETUS EDULIS

Abstract Considering the interest for mushrooms and the demand to search for natural antioxidants and other sources of bioactive-compounds, the aim of this study was to investigate the content of bioactive compounds of two widely used wild edible mushrooms Boletus edulis f. beticola and Boletus edulis f. pinicola collected at Jelgava and Riga regions in Latvia. Ash amount was determined to characterize the mineral content; protein was determined by Lowry method (325-526 mg g -1 of dried mushrooms). Using HPLC the phenolic compounds like gallic acid, caffeic acid, catechin, epicatechin and rutin were detected and quantified. β-carotene and lycopene were determined. DPPH assay was used to evaluate free radical-scavenging activity. In water extracts titratable acidity (0.22-0.26 mmol of NaOH per g of dry mushroom matter) and formol number (0.74-1.40 mmol NaOH per g of dry mushroom matter) were determined. The total content of phenols (TP) as determined by Folin-Ciocalteu assay was higher in the water extracts (11.2-12.5 mg of gallic acid equivalents GAE per 1 g of dry mushroom matter) than in methanol extracts (7.3-8.0 mg of GAE per 1 g of dry mushroom matter). The total content of flavonoids (TF) was higher in the water extracts (0.33-0.37 mg of QE per 1 g of dry mushroom matter) than in methanol extracts (0.13 mg of quercetin equivalents QE per 1 g of dry mushroom matter)

Bioactive Compounds in Latvian Wild Berry Juice

Fructose is the dominant monosaccharide in bilberry juice and red bilberry juice, but glucose is dominant in the cranberry juice. Dominant polyphenols are catechine and chlorogenic acid. In the bilberry and red bilberry juices, the most common acids are citric, quinic and tartaric acids, in the cranberry juice – citric, quinic and malic acids. When bilberry juice is heat-treated for 30 min at 98 °C ± 1 °C, HMF content is 2-fold higher than in samples treated at 60 °C ± 1 °C. In solutions from lyophilisates of wild berry juice, turbidity and translucent coloration have been determined

Bioactive Compounds in Latvian Wild Berry Juice

Fructose is the dominant monosaccharide in bilberry juice and red bilberry juice, but glucose is dominant in the cranberry juice. Dominant polyphenols are catechine and chlorogenic acid. In the bilberry and red bilberry juices, the most common acids are citric, quinic and tartaric acids, in the cranberry juice – citric, quinic and malic acids. When bilberry juice is heat-treated for 30 min at 98 C  1 C, HMF content is 2-fold higher than in samples treated at 60 C  1 C. In solutions from lyophilisates of wild berry juice, turbidity and translucent coloration have been determined