2.5. Determination of product recov

2.5. Determination of product recovery
The product recovery of samples after spray drying was calculated according to the following formula, based on dry matter measurements:

product recovery ๐% ผ obtained spray dried powder ๐g bayberry juice ๐g WPI=maltodextrin ๐g

2.6. Determination of moisture content and water activity (aw)
The moisture content of the powder was determined by vacuum drying (Thermoline Scientific, Australia) at 70 °C and 500 mbar for 24 h.

The water activity of the bayberry powder was determined using an AquaLab 3TE Series water activity meter (Decagon, USA). The temperature was maintained at 24.5±0.1 °C during the tests.

All determinations were done in triplicate immediately after spray drying.

2.7. Determination of glass transition temperature (Tg)
The Tg of the powders was determined using a Mettler–Toledo differential scanning calorimeter (mode DSC1).

The transfer of samples from the desiccators to the DSC pan was done in a sealed ‘Dry Box’ containing excess silica gel, to avoid unwanted moisture absorption by the sample. The purge gas used was dry nitrogen.

Indium (Mettler–Toledo standard) was used for temperature and heat flow calibrations. Samples of about 10 mg were scanned in hermetically sealed 40 μl DSC aluminum pans. An empty aluminum pan was used as a reference.

The heating ramp rate was set to 10 °C/min and heat scanned from an equilibrium starting temperature of −10 °C to 120 °C for spray dried bayberry powders and from 0 °C to 180 °C for WPI and maltodextrin.

The midpoint values for glass transition temperature of the samples were calculated using the DSC STARe evaluation software (Mettler–Toledo).

The moisture content for all samples was normalized in a aw of 0.22 environment for 2 weeks before determination and all analyses were done in triplicate.

2.8. Electron spectroscopy for chemical analysis (ESCA)
The ESCA measurements were carried out to determine the surface composition of the spray dried bayberry powder samples with the addition of WPI.

This technique was aimed to measure the relative atomic concentration of carbon, nitrogen, and oxygen in the surface layer of the samples (depth of less than 100 Å).

Because no protein (no nitrogen) was used for the spray drying of maltodextrin– bayberry juices, the surface protein coverage was not analyzed for these samples.

The analysis was performed on a Kratos AXIS Ultra photoelectron spectrometer (Kratos Analytical Ltd, Manchester, UK) with a 150W monochromatic A1 X-ray source, and the procedure was reported elsewhere (Adhikari, Howes, Bhandari et al., 2009; Shrestha, Howes, Adhikari, Wood, & Bhandari, 2007). The protein coverage of the samples was calculated by a matrix inversion method based on the ESCA data (Adhikari, Howes, Bhandari et al., 2009; Fäldt, Bergenstahl, & Carlsson, 1993; Kim, Chen, & Pearce, 2002; Shrestha et al., 2007).


2.9. Statistical analysis
One-way analysis of variance (ANOVA) (using SPSS 10.0 statistics software, SPSS Inc., Chicago, IL) was used for the determination of differences between processes.

The results were expressed as mean ±standard error (SE) and considered significantly different when pb0.05.


3. Results and discussion
3.1. Bayberry juice powder recovery
The spray dried bayberry juice powders were collected from the product collection vessel only, which were used for the calculation of powder recovery.

Particles deposited on the dryer chamber and connection pieces (between the dryer chamber and cyclone) were discarded, because the amounts of the manually swept and collected particles from these parts are variable to each run and might cause unnecessary calculation errors.

The pure whey protein isolate (WPI) and maltodextrin were spray dried as controls, and their powder recovery was about 74% and 67%, respectively (Table 1). The experiment of spray drying of bayberry juice alone was also conducted, but all the juice solids were sticky on the dryer chamber wall and no powder was recovered in the collection vessel.

When 10% of the bayberry juice total solid was replaced by maltodextrin, the powder recovery only rose to about 10% (Table 1), and most of the juice solids were still deposited on the dryer wall. The addition of 20% maltodextrin significantly increased the powder recovery
to about 45%, and 30% of the maltodextrin had a further significant powder recovery of 53%.

Increasing the maltodextrin to 40% and 50% also increased the powder recovery accordingly, but no statistically significant differences were observed when comparing with 30% of maltodextrin addition (Table 1).

ผลลัพธ์ (ไทย) 1:

2.5. กำหนดกู้คืนสินค้าการกู้คืนผลิตภัณฑ์ตัวอย่างหลังจากสเปรย์แห้งคำนวณตามสูตรต่อไปนี้ อิงวัดแห้ง: ผลิตภัณฑ์กู้ ๐ %ผรับพ่นแห้งผง ๐g bayberry น้ำ ๐g WPI = ๐g สารประเภท maltodextrin2.6. การกำหนดความชื้นน้ำและเนื้อหากิจกรรม (อึ้ง)ความชื้นของผงถูกกำหนด โดยผ้าสูญญากาศ (Thermoline วิทยาศาสตร์ ออสเตรเลีย) ที่ 70 ° C และ 500 mbar ใน 24 ชม กิจกรรมน้ำผง bayberry ที่ถูกกำหนดโดยใช้การ AquaLab 3TE ชุดกิจกรรมเครื่องวัดน้ำ (รูปสิบเหลี่ยม สหรัฐอเมริกา) อุณหภูมิถูกเก็บรักษาไว้ที่ 24.5±0.1 ° C ในระหว่างการทดสอบ วิเคราะห์ปริมาณทั้งหมดถูกทำลข้อทันทีหลังจากสเปรย์แห้ง2.7 การกำหนดอุณหภูมิการเปลี่ยนแก้ว (Tg)Tg ของผงพิจารณาใช้ต่าง Mettler – Toledo แคลอรีมิเตอร์ (โหมด DSC1) การโอนย้ายตัวอย่างจากการ desiccators กับกระทะ DSC เสร็จในปิดผนึก 'แห้งกล่อง' เกินซิลิก้าเจล เพื่อหลีกเลี่ยงการดูดซึมความชื้นที่ไม่พึงประสงค์ โดยตัวอย่างที่ประกอบด้วย น้ำมันล้างที่ใช้คือ ไนโตรเจนแห้ง อินเดียม (เล่อร์ – มาตรฐาน) ใช้สำหรับการสอบเทียบการไหลอุณหภูมิและความร้อน ตัวอย่างประมาณ 10 mg ถูกสแกนในสเตนเลสกระทะอลูมิเนียม DSC μl 40 กระทะอลูมิเนียมว่างเปล่าการถูกใช้เป็นการอ้างอิง เครื่องทำความร้อนอัตราลาดถูกตั้งค่าเป็นนาที 10 ° C และความร้อน จากการสมดุลเริ่มต้นอุณหภูมิ −10 องศา C ถึง 120 ° C สำหรับพ่น bayberry ผง และ จาก 0 ° C ถึง 180 ° C สำหรับ WPI และสารประเภท maltodextrin ที่สแกน The midpoint values for glass transition temperature of the samples were calculated using the DSC STARe evaluation software (Mettler–Toledo). The moisture content for all samples was normalized in a aw of 0.22 environment for 2 weeks before determination and all analyses were done in triplicate.2.8. Electron spectroscopy for chemical analysis (ESCA)The ESCA measurements were carried out to determine the surface composition of the spray dried bayberry powder samples with the addition of WPI. This technique was aimed to measure the relative atomic concentration of carbon, nitrogen, and oxygen in the surface layer of the samples (depth of less than 100 Å).Because no protein (no nitrogen) was used for the spray drying of maltodextrin– bayberry juices, the surface protein coverage was not analyzed for these samples. The analysis was performed on a Kratos AXIS Ultra photoelectron spectrometer (Kratos Analytical Ltd, Manchester, UK) with a 150W monochromatic A1 X-ray source, and the procedure was reported elsewhere (Adhikari, Howes, Bhandari et al., 2009; Shrestha, Howes, Adhikari, Wood, & Bhandari, 2007). The protein coverage of the samples was calculated by a matrix inversion method based on the ESCA data (Adhikari, Howes, Bhandari et al., 2009; Fäldt, Bergenstahl, & Carlsson, 1993; Kim, Chen, & Pearce, 2002; Shrestha et al., 2007).2.9. Statistical analysisOne-way analysis of variance (ANOVA) (using SPSS 10.0 statistics software, SPSS Inc., Chicago, IL) was used for the determination of differences between processes. The results were expressed as mean ±standard error (SE) and considered significantly different when pb0.05.3. Results and discussion3.1. Bayberry juice powder recoveryThe spray dried bayberry juice powders were collected from the product collection vessel only, which were used for the calculation of powder recovery. Particles deposited on the dryer chamber and connection pieces (between the dryer chamber and cyclone) were discarded, because the amounts of the manually swept and collected particles from these parts are variable to each run and might cause unnecessary calculation errors.The pure whey protein isolate (WPI) and maltodextrin were spray dried as controls, and their powder recovery was about 74% and 67%, respectively (Table 1). The experiment of spray drying of bayberry juice alone was also conducted, but all the juice solids were sticky on the dryer chamber wall and no powder was recovered in the collection vessel. When 10% of the bayberry juice total solid was replaced by maltodextrin, the powder recovery only rose to about 10% (Table 1), and most of the juice solids were still deposited on the dryer wall. The addition of 20% maltodextrin significantly increased the powder recoveryto about 45%, and 30% of the maltodextrin had a further significant powder recovery of 53%.Increasing the maltodextrin to 40% and 50% also increased the powder recovery accordingly, but no statistically significant differences were observed when comparing with 30% of maltodextrin addition (Table 1).