[Determination of mineral elements in eight pear varieties by ICP-MS after microwave-assisted digestion].

A study was carried out on the contents of mineral elements such as Na, K, Ca, Mg, Zn, Cu, Fe, Mn and B in eight different pear varieties by ICP-MS after microwave-assisted digestion. The results indicated that the main elements of the eight pears are similar, but the content of each element is different. The content of K is the highest in the detected pears, followed by Mg, Ca and Na. Compared with the reference value of AIJN (Association of Industry of Juices and Nectars from fruits and vegetables of the European Union), the range scale of K, Mg, and Ca was higher than that of the AIJN, while the content of Na element was lower than that of the AIJN, and other elements content was consistent with it.

Changes in the volatile compounds and chemical and physical properties of Kuerle fragrant pear (Pyrus serotina Reld) during storage.

Volatiles from stored Kuerle fragrant pears (Pyrus serotina Reld) were studied using high-resolution gas chromatography and the solid-phase microextraction (SPME) method of gas chromatography/mass spectrometry (GC/MS). The dominant components were hexanal, ethyl hexanoate, ethyl butanoate, ethyl acetate, hexyl acetate, ethanol, alpha-farnesene, butyl acetate, and ethyl (E,Z)-2,4-decadienoate. By using GC-olfactometry, it demonstrated that the volatile compounds from SPME were responsible for the aroma of the Kuerle fragrant pear. The levels of sugars, organic acids, and phenolic acids in Kuerle fragrant pears were investigated using high-performance liquid chromatography (HPLC). Fructose was the dominant sugar, followed by glucose and sucrose. With increasing storage time, sucrose levels decreased; however, changes in fructose and glucose levels were not remarkable. There was a slight decrease in flesh firmness during storage. The general soluble solids concentration (SSC) declined slightly after 5 months storage. Some aroma-related volatile components increased during storage, while others decreased, especially the esters. The organic acids and phenolic acids also changed. The flavor of the Kuerle fragrant pears was affected by the change of volatile compounds and changes in chemical and physical properties.