Abstract: The present disclosure discloses a marker for screening and distinguishing NFC apple juice based on non-targeted metabolomics and use thereof, relating to the technical field of distinguishing of juice. The marker for distinguishing NFC apple juice disclosed in the present disclosure is selected from the following molecules: gallocatechin, catechin, taxifolin, p-hydroxybenzaldehyde, 5-methoxysalicylic acid, azelaic acid, caffeic acid, chlorogenic acid, epicatechin, eriodictyol, ferulic acid, isoquercitrin, naringenin, n-fructosyl isoleucine, p-coumaraldehyde, p-coumaric acid, phloretin, phlorizin, procyanidin B1, quercetin-3-O-galactoside and rutin. The above markers may be used for distinguishing the NFC apple juice and the FC apple juice, and have relatively high accuracy.

Abstract: A spray nozzle with posterior positioned switch includes a body (1), a shaft (2) and a pressing bar (3). The body (1) includes a plug (4) blocking off an inner channel. The plug (4) has a through hole (41) in communication with the inner channel. The pressing bar (3) is hinged on a posterior of the body (1). The shaft (2) extends outside the body (1) and is connected to the pressing bar (3). The body (1) includes a first compression spring (5) to push the shaft (2) forward to block off the through hole (41). A positioning mechanism is disposed between the body (1) and the pressing bar (3). The positioning mechanism is controlled by fingers except for thumb to stop the depressed pressing bar (3) in a case that a handle (11) of the body (1) is held in hand.