Comparative Study Of The Nutrients Of Different Garlic Bulbs Products

This study was launched from four aspects,including experiments about differentgrowth stages, different varieties, different pretreatment methods and differences before andafter processing, comprehensivly surveyed some indicators like nutrients, active ingredientsenzyme activities and so on, studied the variation of chemical compositions during differentgrowth stages, found the differences of different varieties, compared the effects on resultsafter different pretreatments, and the changes of chemical compositions before and afterprocessing, aiming at providing a reference for the further study of functions of garlic anddevelopment of new products. The samples for experiment about different growth stages weretaken from the enlargement of bulbs to preharvest, samples for experiment about differentvarieties were “jin xiang Ⅲ”, cang shan and yunnan garlics. Took megathermally drying andfreeze drying as two treatments for the experiment about different treatment methods, andtook normal garlic and black garlic as samples for experiment about before and afterprocessing.The main conclusions were as follows:1. The polyphenol was extracted from Blackgarlic by microwave-assisted extraction,and the extraction process was optimized. First took ethanol concentration,microwavepower,extraction time and material-liquid ratio as the key single factors for the gradientexperiments, then took L9(34) orthogonal experiment, the results showed that the optimumultrasonic extraction conditions were as follows: the concentration of ethanol was50%, themicrowave power was300W, the extraction time was30s and the ratio of solid to liquid was1:30.2. The result of experiment about different stages showed that the trends of differentindicators were different with the changes of growth stages: the contents of free amino acidand polyphenol changed wavly; the content of soluble sugar first decreased then increased;the chemical compositions of garlic oil were mainly esters, alcohols and alkanes, there werenearly no sulfide compounds in the samples took during the front part of the growth stages.The types and relative contents of sulfide compounds gradually increased, the allitridin couldbe detected in the last period of growth.3. The result of experiment about different varieties of garlic showed that there weredifferences among different varieties, as follows: the content of soluble sugar of yun nangarlic was higher than that of the others; the contents of free amino acid and vitamin C ofcang shan garlic were higher than those of the others; the contents of other several indicators (including soluble proteins, polyphenols, allicin, CAT and APX) were higher than those of theothers; the types of chemical compositions of garlic oil from different varieties of garlics werenearly the same, mainly were sulfide compounds, but the relative content of each compositionwas different from the other, the relative contents of allitridin of garlic oils from differentvarieties of garlics were all the highest.4. The result of experiment about different treatments showed that the impacts to sev-eral indicators from different treatments were different, as follows: the contents of free aminoacid and soluble sugar were higher in the sample which was freeze tried than megathermallydried; the content of polyphenols was higher in the sample which was megathermally driedthan freeze tried; the types of chemical compositions of garlic oil from garlics after freezedried and megathermally dried were nearly the same, meanly were alkanes and esters, therelative content of sulfide compounds was low, so we could summary that there were nearlyno differences between the garlic oils from samples after two knid of treatments.5. The result of experiment about before and after processing showd that the chemicalcompositions and their contents changed greatly after a long period of fermentation. Thecontents of polyphenols and vitamin C of black garlic were higher than those of normal garlic;the contents of several other indicators of normal garlic were higher than those of black garlic;the oils were extracted from normal and black garlics and their chemical composition wereanalyzed, the result showed that there were mainly sulfide compounds in the garlic oil fromnormal garlic, and the relative content of allitridin was very high; it showed that allitridin andother elements which should exist could not be detected any longer, while the relativecontents of esters,alkanes greatly increased.