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Determination of basic nutritional parameters in edible insects
Korček, Jakub ; Štursa, Václav (referee) ; Diviš, Pavel (advisor)
In this bachelor thesis is dicussed nutritional value of chosen insect species. Analysed samples consisted of worms, crickets and locusts. Analysed parameters were: total nitrogen, crude protein, total lipids and content of chosen elements. Total lipids were, after homogenization, determined by Soxhlet method, using diethyl ether as a solvent. Prior to protein and element determination, samples did undergo Kjehldal digestion process, using sulfuric acid. Weiniger catalyst was only added to samples digested for protein measurement. Element content was determined by optical emission spectrometry with inductively coupled plasma (ICP-OES). Crude protein was determined by Kjeldahl method. The highest protein content was determined in crickets. (75 ± 5) %. Locusts contained the highest lipid content (33 ± 2) %. We also found out, that samples were rich in calcium, potassium, manganese and zinc, which are all important elements for the proper functioning of our body. The results of this thesis prove, that insects can present nutritionally important food.
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Analysis of onion and garlic samples of different geographical origin
Korček, Jakub ; Mikulíková, Renata (referee) ; Diviš, Pavel (advisor)
Presented master thesis dealt with the analysis of garlic and onion samples and tried to find correlations between chemical composition and country of origin. The parameters examined were dry content, crude protein content, concentration of phenolic compunds, carbohydrate content (fructose, glucose), alliin content and concentration of selected elements (P, Mg, Ca, Na, K, Fe, Zn). Average content of dry matter of fresh samples was 35,84 ±2,12 g/100 g and of dehydrated samples was 90,61 ±2,90 g/100 g. Concentration of phenolic compounds was measured spectrophotometrically with Folin-Ciocault reagent. Average phenolic compounds content of samples was 0,1840 ±0,1286 GAE g/100 g. Crude protein content was measured by Kjeldahl method, and calculated from total nitrogen content. Carbohydrates were measured by HPLC-ELSD after hydrolysis of fructans. Average content of fructose of garlic samples was 57,014 ±0,863 g/100 g, of onion samples was 33,718 ±1,168 g/100 g. Average content of glucose of onion samples was 22,633 ±0,405 g/100 g. Alliin content was measured by HPLC-DAD method. Average alliin content of fresh samples was 4,644 ±0,446 g/100 g and of dehydrated samples was 1,962 ±0,180 g/100 g. Elemental analysis was conducted by ICP-OES method. Average concentration of selected elements was: P 2,15 ±0,11 mg/g, Mg 0,638 ±0,03 mg/g, Ca 1,246 ±0,05 mg/g, Na 0,550 ±0,08 mg/g, K 7,49 ±0,41 mg/g, Fe 79,3 ±6,16 mg/kg, Zn 11,4 ±3,33 mg/kg. Obtained data were statistically processed on significance level 0,05. Based on the principal components analysis, it was found, that the best parameters to differentiate samples from Czechia, Poland and Ukraine from other countries were content of nitrogen, phosphorus, magnesium, sodium and calcium. It was also discovered, that genus differences between onion and garlic have greater significance than geographical differences.
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Analysis of onion and garlic samples of different geographical origin
Korček, Jakub ; Mikulíková, Renata (referee) ; Diviš, Pavel (advisor)
Presented master thesis dealt with the analysis of garlic and onion samples and tried to find correlations between chemical composition and country of origin. The parameters examined were dry content, crude protein content, concentration of phenolic compunds, carbohydrate content (fructose, glucose), alliin content and concentration of selected elements (P, Mg, Ca, Na, K, Fe, Zn). Average content of dry matter of fresh samples was 35,84 ±2,12 g/100 g and of dehydrated samples was 90,61 ±2,90 g/100 g. Concentration of phenolic compounds was measured spectrophotometrically with Folin-Ciocault reagent. Average phenolic compounds content of samples was 0,1840 ±0,1286 GAE g/100 g. Crude protein content was measured by Kjeldahl method, and calculated from total nitrogen content. Carbohydrates were measured by HPLC-ELSD after hydrolysis of fructans. Average content of fructose of garlic samples was 57,014 ±0,863 g/100 g, of onion samples was 33,718 ±1,168 g/100 g. Average content of glucose of onion samples was 22,633 ±0,405 g/100 g. Alliin content was measured by HPLC-DAD method. Average alliin content of fresh samples was 4,644 ±0,446 g/100 g and of dehydrated samples was 1,962 ±0,180 g/100 g. Elemental analysis was conducted by ICP-OES method. Average concentration of selected elements was: P 2,15 ±0,11 mg/g, Mg 0,638 ±0,03 mg/g, Ca 1,246 ±0,05 mg/g, Na 0,550 ±0,08 mg/g, K 7,49 ±0,41 mg/g, Fe 79,3 ±6,16 mg/kg, Zn 11,4 ±3,33 mg/kg. Obtained data were statistically processed on significance level 0,05. Based on the principal components analysis, it was found, that the best parameters to differentiate samples from Czechia, Poland and Ukraine from other countries were content of nitrogen, phosphorus, magnesium, sodium and calcium. It was also discovered, that genus differences between onion and garlic have greater significance than geographical differences.
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Determination of basic nutritional parameters in edible insects
Korček, Jakub ; Štursa, Václav (referee) ; Diviš, Pavel (advisor)
In this bachelor thesis is dicussed nutritional value of chosen insect species. Analysed samples consisted of worms, crickets and locusts. Analysed parameters were: total nitrogen, crude protein, total lipids and content of chosen elements. Total lipids were, after homogenization, determined by Soxhlet method, using diethyl ether as a solvent. Prior to protein and element determination, samples did undergo Kjehldal digestion process, using sulfuric acid. Weiniger catalyst was only added to samples digested for protein measurement. Element content was determined by optical emission spectrometry with inductively coupled plasma (ICP-OES). Crude protein was determined by Kjeldahl method. The highest protein content was determined in crickets. (75 ± 5) %. Locusts contained the highest lipid content (33 ± 2) %. We also found out, that samples were rich in calcium, potassium, manganese and zinc, which are all important elements for the proper functioning of our body. The results of this thesis prove, that insects can present nutritionally important food.
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