| The loquat(Eriobotrya japonica Thunb Lindl.)is an evergreen tree of the genus Eriobotrya in the family Rosaceae,subfamily Apple,and is native to southern China and is now widely grown throughout the world.Loquat honey has a unique aromatic odour and colour.There are few studies on loquat honey,especially on the changing patterns of loquat honey during brewing,and it is important to study loquat honey systematically in the Taihu Lake area of Suzhou,which is widely planted with loquat and is an important local nectar source plant.In this study,other monofloral honeys,loquat honeys from other regions and Suzhou loquat honey were used as experimental materials to investigate the characteristic volatile substances of Suzhou loquat honey and the change patterns of the main components during brewing by bees Specific results are as follows:(1)Volatile components,sugars and minerals were measured in loquat honey and 10 monofloral honeys of acacia,wattle,citrus,buckwheat,linden,motherwort,astragalus,campsis grandiflora,sebifer and eucalyptus,and the results showed that three characteristic peaks were found in loquat honey at 33.498 min,34.988 min and 44.197 min,which were not detected in the other 10 monofloral honeys,so that These three substances were identified as characteristic components of loquat honey,and were verified as p-methoxybenzyl alcohol,p-methoxybenzaldehyde and pmethoxybenzoic acid after comparison with the standard mass spectrometry library and external standard method.The fructose,glucose and sucrose contents of loquat honey were significantly different from those of the other 10 monofloral honeys,and the fructoglucose ratio in loquat honey was lower,at 1.30.The sodium content of loquat honey was 12.52±0.30 mg/kg and the magnesium content was 19.06±1.60 mg/kg,which were significantly different from those of the other 10 monofloral honeys,p<0.05.(2)The volatile components,sugars and minerals of loquat honey from five regions,namely Suzhou,Chengdu,Xuancheng,Huangshan and Hangzhou,were determined and the results showed that there were significant differences in the contents of each substance between Suzhou and the other five regions,with the contents of three volatile substances,namely p-methoxybenzaldehyde,pmethoxybenzyl alcohol and p-methoxybenzoic acid,in Suzhou loquat honey being 11.56±1.24μ This difference may be responsible for the unique aromatic odour of Suzhou loquat honey.The content of sucrose and maltose in Suzhou loquat honey was significantly lower than that of loquat honey from other regions,and the mineral content of Suzhou loquat honey was significantly different from that of loquat honey from other regions,except for sodium,magnesium,potassium and manganese.(3)The moisture,volatile matter,sugars and amylase contents of 60 samples of Suzhou loquat honey were measured from 1 to 20 d.The results showed that the moisture content of Suzhou loquat honey showed an overall decreasing trend during the brewing process,and this trend was closely related to the change in ambient temperature;the amylase content increased from 11.13[mL(g*h)]to 12.73[mL(g*h)],with a non-significant difference of p>0.05;the content of fructose,glucose and maltose gradually increased and the content of maltose gradually decreased;the difference in the content of the three characteristic volatile substances showed a stable trend of p>0.05,with a non-significant difference between the 1st5th and 15th-20th d of loquat honey brewing.In this study,the content of characteristic volatile substances and their main components were analysed during the brewing process of loquat honey in Suzhou.The results of this study help us to understand the changes of the main indicators during the brewing process and provide some data support for the future determination of the quality of loquat honey.It also provides an important theoretical basis for identifying loquat honey and classifying the geographical origin of loquat honey. |
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