Abstract: Present invention teaches the method of using a keratin hydrolysis peptide (“KHP”) solution to accelerate the ripening and color change of the coffee fruits, to increase the reducing sugar content, and to decrease the chlorogenic acid content in coffee beans. By selectively choosing specific weights of feathers and water, and treating the mixture, though one embodiment does not have water mixed in, to a high-temperature high-pressure hydrolysis process, the resulting solution is confirmed to contain at least 253 peptides and then applied to the leaf surface of coffee plants at different growth stages. Optionally, the KHP solution can be diluted by water, as taught in the specification, before applying to the leaf surface of the coffee plants.

Abstract: A bubble generating system includes a centrifugal pump which has a front frame and a rear frame, wherein a plurality of inlets are defined in the front frame and communicates with a center passage of the centrifugal pump. A water tank is connected with the centrifugal pimp and supplies water into the centrifugal pump. An air supplier has a plurality of supply pipes connected with the inlets so as to introduce high pressurized air into the centrifugal pump. A tub has a first pipe connected to nozzles of the tub and a second pipe recycles the water in the tub back to the centrifugal pump.