UL Prospector
Prospector

成功!

成功保存搜索结果
39 条结果
Aluminium Ammonium Sulphate FCC Canton Chem, Inc. Aluminium Ammonium Sulphate FCC appears as a colorless crystalline to white colored granules or powder. This product has a molecular weight of 453.33, an assay of 99.5 - 100.5%, and is denoted by the CAS number 7784-26-1. This product is soluble in water,...展开 Aluminium Ammonium Sulphate FCC appears as a colorless crystalline to white colored granules or powder. This product has a molecular weight of 453.33, an assay of 99.5 - 100.5%, and is denoted by the CAS number 7784-26-1. This product is soluble in water, insoluble in alcohol, and is freely, but slowly, soluble in glycerin. Aluminium Ammonium Sulphate FCC is used in food and beverage products as a mineral fortifier. 收起
Aluminium Potassium Sulphate FCC Canton Chem, Inc. Aluminium Potassium Sulphate FCC appears as large, transparent crystals or crystalline fragments. This product has a molecular weight of 474.38, an assay of 99.5 - 100.5%, and is denoted by the CAS number 7784-24-9. This product is soluble in water, and ...展开 Aluminium Potassium Sulphate FCC appears as large, transparent crystals or crystalline fragments. This product has a molecular weight of 474.38, an assay of 99.5 - 100.5%, and is denoted by the CAS number 7784-24-9. This product is soluble in water, and insoluble in alcohol. Aluminium Potassium Sulphate FCC is used in food and beverage products as a mineral fortifier. 收起
Aluminium Sulphate FCC Canton Chem, Inc. Aluminium Sulphate FCC appears as a white colored powder, shining plates, or crystalline fragments. This product has a molecular weight of 342.10, an assay of 99.5 - 101.7%, and is denoted by the CAS number 17927-65-0. This product is soluble in water. Al...展开 Aluminium Sulphate FCC appears as a white colored powder, shining plates, or crystalline fragments. This product has a molecular weight of 342.10, an assay of 99.5 - 101.7%, and is denoted by the CAS number 17927-65-0. This product is soluble in water. Aluminium Sulphate FCC is used in food and beverage products as a mineral fortifier. 收起
Ammonium Bicarbonate FCC Canton Chem, Inc. Ammonium Bicarbonate FCC appears as a white crystal or crystalline powder. This product has a molecular weight of 79.06, an assay of 99.0 - 100.5%, and is denoted by the CAS number 1066-33-7. This product is soluble in water, and insoluble in alcohol. Amm...展开 Ammonium Bicarbonate FCC appears as a white crystal or crystalline powder. This product has a molecular weight of 79.06, an assay of 99.0 - 100.5%, and is denoted by the CAS number 1066-33-7. This product is soluble in water, and insoluble in alcohol. Ammonium Bicarbonate FCC is used in food and beverage products as a mineral fortifier. 收起
Ammonium Carbonate FCC Canton Chem, Inc. Ammonium Carbonate FCC appears as a white powder, or as a hard, white or translucent mass. This product has a molecular weight of 175.14, an assay of 30.0 - 34.0%, and is denoted by the CAS number 506-87-6. This product is freely soluble in water. Ammoniu...展开 Ammonium Carbonate FCC appears as a white powder, or as a hard, white or translucent mass. This product has a molecular weight of 175.14, an assay of 30.0 - 34.0%, and is denoted by the CAS number 506-87-6. This product is freely soluble in water. Ammonium Carbonate FCC is used in food and beverage products as a mineral fortifier. 收起
Ammonium Phosphate Dibasic FCC Canton Chem, Inc. Ammonium Phosphate Dibasic FCC appears as white colored crystals, crystalline powder, or granules. This product has a molecular weight of 132.06, an assay of 96.0 - 102.0%, and is denoted by the CAS number 7783-28-0. This product is freely soluble in wate...展开 Ammonium Phosphate Dibasic FCC appears as white colored crystals, crystalline powder, or granules. This product has a molecular weight of 132.06, an assay of 96.0 - 102.0%, and is denoted by the CAS number 7783-28-0. This product is freely soluble in water. Ammonium Phosphate Dibasic FCC is used in food and beverage products as a mineral fortifier. 收起
Ammonium Phosphate Monobasic FCC Canton Chem, Inc. Ammonium Phosphate Monobasic FCC appears as white colored crystals, crystalline powder, or granules. This product has a molecular weight of 115.03, an assay of 96.0 - 102.0%, and is denoted by the CAS number 7722-76-1. This product is soluble in water. Am...展开 Ammonium Phosphate Monobasic FCC appears as white colored crystals, crystalline powder, or granules. This product has a molecular weight of 115.03, an assay of 96.0 - 102.0%, and is denoted by the CAS number 7722-76-1. This product is soluble in water. Ammonium Phosphate Monobasic FCC is used in food and beverage products as a mineral fortifier. 收起
ATUREX ® MAG95 Monoammonium Glycyrrhizinate Aturex Group ATUREX ® MAG95 Monoammonium Glycyrrhizinate is extracted from natural plant licorice and is a white powder. It’s the ideal natural sweetener material. It has applications in the food industry.
ATUREX® 1000IU Tocopherol Aturex Group ATUREX® 1000IU Tocopherol is a D-α Tocopherol which is a vitamin E supplement. It is a light yellow to brownish red, clear, viscous oil. It has a mild, characteristic odor and taste, and its biological activity is three times higher than synthetic VE. It ...展开 ATUREX® 1000IU Tocopherol is a D-α Tocopherol which is a vitamin E supplement. It is a light yellow to brownish red, clear, viscous oil. It has a mild, characteristic odor and taste, and its biological activity is three times higher than synthetic VE. It has a absorbance level of 254nm-284nm and a potency of 1000IU. ATUREX® 1000IU Tocopherol is used as a natural antioxidant, nutrition enhancer, and in the food and beverage industry. 收起
ATUREX® 1000IU Tocopheryl Acetate Aturex Group ATUREX® 1000IU Tocopheryl Acetate is a vitamin E supplement. It is a clear, pale yellow viscous, oil-like liquid. It has a slight vegetable oil aroma and a mild taste. It has a potency of 1000IU. ATUREX® 1000IU Tocopheryl Acetate is used in the food indus...展开 ATUREX® 1000IU Tocopheryl Acetate is a vitamin E supplement. It is a clear, pale yellow viscous, oil-like liquid. It has a slight vegetable oil aroma and a mild taste. It has a potency of 1000IU. ATUREX® 1000IU Tocopheryl Acetate is used in the food industry. 收起
ATUREX® 1100IU Tocopherol Aturex Group ATUREX® 1100IU Tocopherol is a D-α Tocopherol which is a vitamin E supplement. It is a light yellow to brownish color, clear, viscous oil. It has a mild, characteristic odor and taste, and its biological activity is three times higher than synthetic VE. I...展开 ATUREX® 1100IU Tocopherol is a D-α Tocopherol which is a vitamin E supplement. It is a light yellow to brownish color, clear, viscous oil. It has a mild, characteristic odor and taste, and its biological activity is three times higher than synthetic VE. It has a absorbance level of 254nm-284nm and a potency of 1100IU. ATUREX® 1100IU Tocopherol is used as a natural antioxidant, nutrition enhancer, and in the food and beverage industry. 收起
ATUREX® 1100IU Tocopheryl Acetate Aturex Group ATUREX® 1100IU Tocopheryl Acetate is a vitamin E supplement. It is a clear pale yellow, viscous oil having a slight vegetable oil aroma and a mild taste. It has a potency of 1100IU and is a good antioxidant. ATUREX® 1100IU Tocopheryl Acetate is used in th...展开 ATUREX® 1100IU Tocopheryl Acetate is a vitamin E supplement. It is a clear pale yellow, viscous oil having a slight vegetable oil aroma and a mild taste. It has a potency of 1100IU and is a good antioxidant. ATUREX® 1100IU Tocopheryl Acetate is used in the food industry. 收起
ATUREX® 1185IU Tocopheryl Acid Succinate Aturex Group ATUREX® 1185IU Tocopheryl Acid Succinate is a D-α Tocopherol which is a vitamin E supplement. It is a white to off-white crystalline power with little or no odor or taste. It has an absorbance level of 254mn-284mn and is a good antioxidant. ATUREX® 1185IU...展开 ATUREX® 1185IU Tocopheryl Acid Succinate is a D-α Tocopherol which is a vitamin E supplement. It is a white to off-white crystalline power with little or no odor or taste. It has an absorbance level of 254mn-284mn and is a good antioxidant. ATUREX® 1185IU Tocopheryl Acid Succinate is used in dietary foods and in the food industry. 收起
ATUREX® 1200IU Tocopherol Aturex Group ATUREX® 1200IU Tocopherol is a D-α Tocopherol, which is a vitamin E supplement. It is a natural antioxidant and a nutrition enhancer. It is a light yellow to brownish red, clear, viscous oil. It has a mild, characteristic odor and taste. It has a absorba...展开 ATUREX® 1200IU Tocopherol is a D-α Tocopherol, which is a vitamin E supplement. It is a natural antioxidant and a nutrition enhancer. It is a light yellow to brownish red, clear, viscous oil. It has a mild, characteristic odor and taste. It has a absorbance level of 254nm-284nm and a potency of 1200IU. ATUREX® 1200IU Tocopherol is a additive used in food and beverages. 收起
ATUREX® 1200IU Tocopheryl Acetate Aturex Group ATUREX® 1200IU Tocopheryl Acetate is a vitamin E supplement. It is a clear,pale yellow, viscous oil having a slight vegetable oil aroma and a mild taste. It has a potency of 1200IU and is a good antioxidant. ATUREX® 1200IU Tocopheryl Acetate is used in th...展开 ATUREX® 1200IU Tocopheryl Acetate is a vitamin E supplement. It is a clear,pale yellow, viscous oil having a slight vegetable oil aroma and a mild taste. It has a potency of 1200IU and is a good antioxidant. ATUREX® 1200IU Tocopheryl Acetate is used in the food industry. 收起
ATUREX® 1210IU Tocopheryl Acid Succinate Aturex Group ATUREX® 1210IU Tocopheryl Acid Succinate is a vitamin E supplement. It is a white to off-white crystalline powder with little or no odor or taste. It has an absorbance level of 254mn-284mn, a potency of 1210IU and is a good antioxidant. ATUREX® 1210IU Toc...展开 ATUREX® 1210IU Tocopheryl Acid Succinate is a vitamin E supplement. It is a white to off-white crystalline powder with little or no odor or taste. It has an absorbance level of 254mn-284mn, a potency of 1210IU and is a good antioxidant. ATUREX® 1210IU Tocopheryl Acid Succinate is used in dietary foods and in the food industry. 收起
ATUREX® 1300IU Tocopherol Aturex Group ATUREX® 1300IU Tocopherol is a vitamin E supplement. It is a light yellow to brownish red, clear, viscous oil. It has a mild, characteristic odor and taste, and its biological activity is three times higher than synthetic VE. It has a absorbance level of ...展开 ATUREX® 1300IU Tocopherol is a vitamin E supplement. It is a light yellow to brownish red, clear, viscous oil. It has a mild, characteristic odor and taste, and its biological activity is three times higher than synthetic VE. It has a absorbance level of 254nm-284nm and a potency of 1300IU. ATUREX® 1300IU Tocopherol is used as a natural antioxidant, nutrition enhancer, and in the food and beverage industry. 收起
ATUREX® 25 Toco Aturex Group ATUREX® 25 Toco is a natural antioxidant and nutrition enhancer, without organic solvent and metal ions. It is a lightish yellow to brownish red viscous oil and it has a vegetable oil taste. It has a total VE of 25% or greater. ATUREX® 25 Toco is used in ...展开 ATUREX® 25 Toco is a natural antioxidant and nutrition enhancer, without organic solvent and metal ions. It is a lightish yellow to brownish red viscous oil and it has a vegetable oil taste. It has a total VE of 25% or greater. ATUREX® 25 Toco is used in food and beverages. 收起
ATUREX® 50 Toco Aturex Group ATUREX® 50 Toco is a mixed tocopherol. It is a natural antioxidant and nutrition enhancer, without organic solvent and metal ions. It is a brownish to light yellow color and it is in liquid form. It has a mild and special oil with medium viscosity and its...展开 ATUREX® 50 Toco is a mixed tocopherol. It is a natural antioxidant and nutrition enhancer, without organic solvent and metal ions. It is a brownish to light yellow color and it is in liquid form. It has a mild and special oil with medium viscosity and its total VE is 50% or greater.. ATUREX® 50 Toco is used in food and beverages. 收起
ATUREX® 70 RP Aturex Group ATUREX® 70 RP is a rice protein that is hypoallergenic and contains many amino acids. It is a primrose yellow color in the form of fine powder. It has no odor and no taste and is 70% protein. ATUREX® 70 RP is used in baking products, dairy products, nutr...展开 ATUREX® 70 RP is a rice protein that is hypoallergenic and contains many amino acids. It is a primrose yellow color in the form of fine powder. It has no odor and no taste and is 70% protein. ATUREX® 70 RP is used in baking products, dairy products, nutritious food, health food, and beverage products. 收起
ATUREX® 70 Toco Aturex Group ATUREX® 70 Toco is a mixed tocopherol. It is a natural antioxidant and nutrition enhancer, without organic solvent and metal ions. It is a brownish to light yellow color and it comes in the form of a transparent liquid with middle viscosity. It has a mild...展开 ATUREX® 70 Toco is a mixed tocopherol. It is a natural antioxidant and nutrition enhancer, without organic solvent and metal ions. It is a brownish to light yellow color and it comes in the form of a transparent liquid with middle viscosity. It has a mild taste and a special odor with a total VE of 70% or greater. ATUREX® 70 Toco is used in food and beverages. 收起
ATUREX® 80 RP Aturex Group ATUREX® 80 RP is a rice protein that is hypoallergenic and contains many amino acids. It is a primrose yellow color in the form of fine powder. It has no odor and no taste and is 80% protein. ATUREX® 80 RP is used in baking products, dairy products, nutri...展开 ATUREX® 80 RP is a rice protein that is hypoallergenic and contains many amino acids. It is a primrose yellow color in the form of fine powder. It has no odor and no taste and is 80% protein. ATUREX® 80 RP is used in baking products, dairy products, nutritious food, health food, and beverage products. 收起
ATUREX® 90 RP Aturex Group ATUREX® 90 RP is a rice protein that is hypoallergenic and contains many amino acids. It is a primrose yellow color in the form of fine powder. It has no odor and no taste and is 90% protein. ATUREX® 90 RP is used in baking products, dairy products, nutri...展开 ATUREX® 90 RP is a rice protein that is hypoallergenic and contains many amino acids. It is a primrose yellow color in the form of fine powder. It has no odor and no taste and is 90% protein. ATUREX® 90 RP is used in baking products, dairy products, nutritious food, health food, and beverage products. 收起
ATUREX® 90 Toco Aturex Group ATUREX® 90 Toco is a mixed tocopherol. It is a natural antioxidant and nutrition enhancer, without organic solvent and metal ions. It is a brownish to light yellow color and is in liquid form. It has a mild taste and special odor and it has a total VE of ...展开 ATUREX® 90 Toco is a mixed tocopherol. It is a natural antioxidant and nutrition enhancer, without organic solvent and metal ions. It is a brownish to light yellow color and is in liquid form. It has a mild taste and special odor and it has a total VE of 90% or greater. ATUREX® 90 Toco is used in foods and beverages. 收起
ATUREX® 90 Wood Sterol Aturex Group ATUREX® 90 Wood Sterol is a wood sterol from wood pulp. It has a high nutritional value and physical activity. It is a white uniform powder with no odor or taste. It is a natural antioxidant, nutritional enhancer, and a food additive with a 90% drying con...展开 ATUREX® 90 Wood Sterol is a wood sterol from wood pulp. It has a high nutritional value and physical activity. It is a white uniform powder with no odor or taste. It is a natural antioxidant, nutritional enhancer, and a food additive with a 90% drying content. ATUREX® 90 Wood Sterol is used in the food and beverage industry. 收起
ATUREX® 95 Soy Sterol Aturex Group ATUREX® 95 Soy Sterol is an additive soy sterol from soybeans. It is a white uniform powder with a mild taste and no odor. It is a natural antioxidant and nutritional enhancer with a 95% dry content. It insoluble in water, soluble in acetone, and ethanol....展开 ATUREX® 95 Soy Sterol is an additive soy sterol from soybeans. It is a white uniform powder with a mild taste and no odor. It is a natural antioxidant and nutritional enhancer with a 95% dry content. It insoluble in water, soluble in acetone, and ethanol. ATUREX® 95 Soy Sterol is a food additive used in food and beverages. 收起
ATUREX® 95 Toco Aturex Group ATUREX® 95 Toco is a mixed tocopherol. It is a natural antioxidant and nutrition enhancer, without organic solvent and metal ions. It is a brownish or light yellow color in liquid form. It has a mild taste with a special odor. It has middle viscosity and ...展开 ATUREX® 95 Toco is a mixed tocopherol. It is a natural antioxidant and nutrition enhancer, without organic solvent and metal ions. It is a brownish or light yellow color in liquid form. It has a mild taste with a special odor. It has middle viscosity and has a total VE of 95% or greater. ATUREX® 95 Toco is used in food and beverages. 收起
ATUREX® 95 Wood Sterol Aturex Group ATUREX® 95 Wood Sterol is a wood sterol from wood pulp. It has a high nutritional value and physical activity. It is a white uniform powder with no odor or taste. It is a natural antioxidant, nutritional enhancer, and a food additive with a 95% drying con...展开 ATUREX® 95 Wood Sterol is a wood sterol from wood pulp. It has a high nutritional value and physical activity. It is a white uniform powder with no odor or taste. It is a natural antioxidant, nutritional enhancer, and a food additive with a 95% drying content. ATUREX® 95 Wood Sterol is used in the food and beverage industry. 收起
ATUREX® 97 Plant Sterol Ester Aturex Group ATUREX® 97 Plant Sterol Ester is a product with typical fat like properties, prepared by plant sterols with fatty acids derived from food grade vegetable oils. It comes in two forms; a pale yellow liquid and a creamy white solid. It is 97% sterol esters a...展开 ATUREX® 97 Plant Sterol Ester is a product with typical fat like properties, prepared by plant sterols with fatty acids derived from food grade vegetable oils. It comes in two forms; a pale yellow liquid and a creamy white solid. It is 97% sterol esters and is a natural antioxidant, nutrition enhancer, and food additive. ATUREX® 97 Plant Sterol Ester is used in food and beverages. 收起
ATUREX® D-alpha Tocopherol Acid Glycol1000 Succinate Aturex Group ATUREX® D-alpha Tocopherol Acid Glycol1000 Succinate is a natural vitamin E supplement. It is a natural antioxidant and a nutritional enhancer. It is a light yellow to a yellow waxy solid. It has no characteristic odor or smell. ATUREX® D-alpha Tocopherol...展开 ATUREX® D-alpha Tocopherol Acid Glycol1000 Succinate is a natural vitamin E supplement. It is a natural antioxidant and a nutritional enhancer. It is a light yellow to a yellow waxy solid. It has no characteristic odor or smell. ATUREX® D-alpha Tocopherol Acid Glycol1000 Succinate is used in the food and beverage industry. 收起
Benzoic Acid FCC Canton Chem, Inc. Benzoic Acid FCC appears as white colored crystals. This product has a molecular weight of 122.12, an assay of 99.5 - 100.5%, and is denoted by the CAS number 65-85-0. This product is soluble in boiling water, freely soluble in alcohol, chloroform, and et...展开 Benzoic Acid FCC appears as white colored crystals. This product has a molecular weight of 122.12, an assay of 99.5 - 100.5%, and is denoted by the CAS number 65-85-0. This product is soluble in boiling water, freely soluble in alcohol, chloroform, and ether. Benzoic Acid FCC is used in food and beverage products as a mineral fortifier. 收起
Calcium Acetate FCC Canton Chem, Inc. Calcium Acetate FCC appears as a white colored fine, bulky powder. This product has a molecular weight of 158.17, an assay of 99.0 - 100.5%, and is denoted by the CAS number 62-54-4. This product is freely soluble in water, and slightly soluble in alcohol...展开 Calcium Acetate FCC appears as a white colored fine, bulky powder. This product has a molecular weight of 158.17, an assay of 99.0 - 100.5%, and is denoted by the CAS number 62-54-4. This product is freely soluble in water, and slightly soluble in alcohol. Calcium Acetate FCC is used in food and beverage products as a mineral fortifier. 收起
Calcium Carbonate FCC Canton Chem, Inc. Calcium Carbonate FCC appears as a colorless to white microcrystalline powder. This product has a molecular weight of 100.09, an assay of 98.0 - 100.5%, and is denoted by the CAS number 471-34-1. This product is practically insoluble in water and alcohol....展开 Calcium Carbonate FCC appears as a colorless to white microcrystalline powder. This product has a molecular weight of 100.09, an assay of 98.0 - 100.5%, and is denoted by the CAS number 471-34-1. This product is practically insoluble in water and alcohol. Calcium Carbonate FCC is used in food and beverage products as a mineral fortifier. 收起
Calcium Chloride Anhydrous FCC Canton Chem, Inc. Calcium Chloride Anhydrous FCC appears as a deliquescent, white colored granules or powder. This product has a molecular weight of 110.98, an assay of 93.0 - 100.5%, and is denoted by the CAS number 10043-52-4. This product is soluble in water, and slight...展开 Calcium Chloride Anhydrous FCC appears as a deliquescent, white colored granules or powder. This product has a molecular weight of 110.98, an assay of 93.0 - 100.5%, and is denoted by the CAS number 10043-52-4. This product is soluble in water, and slightly soluble in alcohol. Calcium Chloride Anhydrous FCC is used in food and beverage products as a mineral fortifier. 收起
Calcium Chloride Dihydrate FCC Canton Chem, Inc. Calcium Chloride Dihydrate FCC appears as white colored granules or powder. This product has a molecular weight of 147.01, an assay of 96.0 - 107.0%, and is denoted by the CAS number 10035-04-8. This product is soluble in water, and slightly soluble in al...展开 Calcium Chloride Dihydrate FCC appears as white colored granules or powder. This product has a molecular weight of 147.01, an assay of 96.0 - 107.0%, and is denoted by the CAS number 10035-04-8. This product is soluble in water, and slightly soluble in alcohol. Calcium Chloride Dihydrate FCC is used in food and beverage products as a mineral fortifier. 收起
D-alpha Tocopherol Acetate Powder Aturex Group D-alpha Tocopherol Acetate Powder is a water-soluble supplement that contains 700IU of pure vitamin E. It is a white or off white powder and it has no odor or taste. D-alpha Tocopherol Acetate Powder is used in nutritional food, bread, snacks, and dairy p...展开 D-alpha Tocopherol Acetate Powder is a water-soluble supplement that contains 700IU of pure vitamin E. It is a white or off white powder and it has no odor or taste. D-alpha Tocopherol Acetate Powder is used in nutritional food, bread, snacks, and dairy products. 收起
Indian Yellow Corn Vijaya Enterprises Indian Yellow Corn, also known as maize in some parts of the world, is one of the largest cereal crops grown on Earth. This staple food can be used as flour, meal, flake, syrup, or kernel. It is used in the production of produce tortillas, bread, porridge...展开 Indian Yellow Corn, also known as maize in some parts of the world, is one of the largest cereal crops grown on Earth. This staple food can be used as flour, meal, flake, syrup, or kernel. It is used in the production of produce tortillas, bread, porridge, breakfast cereals, snack foods, corn syrup, beverages, and many processed foods. This product is used in functional foods and nutrition applications. 收起
Maize Grit Vijaya Enterprises Maize Grit, or corn grits, are dried corn kernels which have been ground into a fine, medium, or coarse texture. The finely ground grits may be used as corn flour to produce gluten-free foods, pastries, cookies, and cakes. It may also be used as a food fi...展开 Maize Grit, or corn grits, are dried corn kernels which have been ground into a fine, medium, or coarse texture. The finely ground grits may be used as corn flour to produce gluten-free foods, pastries, cookies, and cakes. It may also be used as a food filler, a binder, and a thickener. The medium textured grit is used to produce cornbread. The coarse textured grit is used to make polenta, southern style grits, and breaded coatings for fried foods. This product is used in functional foods and nutrition applications. 收起
Yellow Maize Vijaya Enterprises Yellow Maize, also known as yellow corn, is a grain that is one of the largest cereal crops grown on Earth. This staple food can be used as flour, meal, flake, syrup, or kernel. It is used in the production of produce tortillas, bread, porridge, breakfast...展开 Yellow Maize, also known as yellow corn, is a grain that is one of the largest cereal crops grown on Earth. This staple food can be used as flour, meal, flake, syrup, or kernel. It is used in the production of produce tortillas, bread, porridge, breakfast cereals, snack foods, corn syrup, beverages, and many processed foods. This product is used in functional foods and nutrition applications. 收起