2.3.1.2 Antioxidant analysis
Two methods to measure the antioxidant activity are by determining its ability of hydrogen atom donation to a reactive species and/or check its ability to take off any molecules of oxidative initiation. Total antioxidant capacity (TAC) level evaluation can be classified into a direct method and indirect method. Indirect method or in vitro method consists of DPPH radical scavenging activity assay, Trolox equivalent antioxidant capacity (TEAC) and oxygen radical absorbance capacity (ORAC) while direct method or in vivo method usually using ferric ion reducing antioxidant power (FRAP) assay.
The most common assay has been used for antioxidant analysis is by using DPPH radical scavenging activity assay. This assay …show more content…
Phenolic compounds found in the vegetables are simpler form than found in roots or leaves. Most common assay being used to determine the total phenolic content by using Folin reagent. This reagent is not detecting the exact phenolic groups contained in the extract. Total phenolic content in this assay is determined by measuring the discoloration of blue colored complex alkaline of Folin reagent using a spectrophotometer and the reading is expressed as gallic acid …show more content…
Juice was extracted by straining through double fold muslin cloth. Maltodextrin then added with 7% w/v of filtered juice. 1000ml of feed was fed into the spray dryer and spray dried at inlet temperature ranging from 160°C to 190°C, 15 mL/min and 160°C, 20 mL/min. The spray dried powder stored in an airtight jar at room temperature for further analysis.
Preliminary spray drying trials showed that at maltodextrin level of 3% and 5%, most of the material stuck on the chamber wall.
3.2 Spray drying conditions of broccoli juice powder
The feed compromising of maltodextrin and juice was spray dried in Buchi Spray Dryer B-290 (Switzerland). The inlet temperature/measured outlet temperature were 160°C/99°C, 170°C/115°C, 190°C/136°C. The different feed rate was set 15mL/min and 20mL/min. Spray dried broccoli juice powder collected and labeled as A, B, C and D for 160°C,15mL/min, 170°C,15mL/min, 190°C,15mL/min and 160°C,20mL/min respectively. All formulations for spray drying were carried out in duplicates.
3.3 Powder analysis
3.3.1 Product yield
The product yield of spray dried broccoli juice powder was calculated according to the
Two methods to measure the antioxidant activity are by determining its ability of hydrogen atom donation to a reactive species and/or check its ability to take off any molecules of oxidative initiation. Total antioxidant capacity (TAC) level evaluation can be classified into a direct method and indirect method. Indirect method or in vitro method consists of DPPH radical scavenging activity assay, Trolox equivalent antioxidant capacity (TEAC) and oxygen radical absorbance capacity (ORAC) while direct method or in vivo method usually using ferric ion reducing antioxidant power (FRAP) assay.
The most common assay has been used for antioxidant analysis is by using DPPH radical scavenging activity assay. This assay …show more content…
Phenolic compounds found in the vegetables are simpler form than found in roots or leaves. Most common assay being used to determine the total phenolic content by using Folin reagent. This reagent is not detecting the exact phenolic groups contained in the extract. Total phenolic content in this assay is determined by measuring the discoloration of blue colored complex alkaline of Folin reagent using a spectrophotometer and the reading is expressed as gallic acid …show more content…
Juice was extracted by straining through double fold muslin cloth. Maltodextrin then added with 7% w/v of filtered juice. 1000ml of feed was fed into the spray dryer and spray dried at inlet temperature ranging from 160°C to 190°C, 15 mL/min and 160°C, 20 mL/min. The spray dried powder stored in an airtight jar at room temperature for further analysis.
Preliminary spray drying trials showed that at maltodextrin level of 3% and 5%, most of the material stuck on the chamber wall.
3.2 Spray drying conditions of broccoli juice powder
The feed compromising of maltodextrin and juice was spray dried in Buchi Spray Dryer B-290 (Switzerland). The inlet temperature/measured outlet temperature were 160°C/99°C, 170°C/115°C, 190°C/136°C. The different feed rate was set 15mL/min and 20mL/min. Spray dried broccoli juice powder collected and labeled as A, B, C and D for 160°C,15mL/min, 170°C,15mL/min, 190°C,15mL/min and 160°C,20mL/min respectively. All formulations for spray drying were carried out in duplicates.
3.3 Powder analysis
3.3.1 Product yield
The product yield of spray dried broccoli juice powder was calculated according to the