การผลิตเจลาตินไฮโดรไลเสตที่มีฤทธิ์ต้านอนุมูลอิสระจากหนังปลาโดยใช้โปรติเอสจาก Bacillus amyloliquefaciens

Thesis (Ph.D. (Food Science and Technology))--Prince of Songkla University, 201

Effect of Pepsin and Hydrolysis Time on Antioxidative Activity of CollagenHydrolysate from Chicken Feet through Response Surface Methodology

เท้าไก่ใช้เป็นแหล่งของคอลลาเจนและเจลาตินที่มีคุณภาพสูง ซึ่งนำมาผลิตเป็นโปรตีนไฮโดรไลเสตที่สามารถออกฤทธิ์ทางชีวภาพเป็นการทำให้ได้ผลิตภัณฑ์ที่มีมูลค่าเพิ่มมากขึ้น โดยการวิจัยนี้มีวัตถุประสงค์เพื่อศึกษาผลของปริมาณเปปซิน(0.02–5% w/w) ร่วมกับระยะเวลาในการย่อย (2–8 ชั่วโมง) เพื่อผลิตคอลลาเจนไฮโดรไลเสตจากเท้าไก่ต่อความสามารถในการยับยั้งการเกิดออกซิเดชันด้วยวิธีพื้นที่ผิวตอบสนอง (Response Surface Methodology) ซึ่งออกแบบการทดลองแบบ Central Composite Design (CCD) จากผลการวิจัยพบว่า ปริมาณเปปซินร่วมกับระยะเวลาที่ใช้ในการย่อยมีความสัมพันธ์กับปริมาณโปรตีนและปริมาณโปรตีนที่ไม่ชอบน้ำโดยจะเพิ่มมากขึ้นเมื่อเพิ่มปริมาณเปปซิน อีกทั้งยังสัมพันธ์กับความสามารถในการต้านอนุมูลอิสระด้วยวิธี ABTS ที่จะเพิ่มมากขึ้นในระดับหนึ่งและลดลงเมื่อปริมาณเปปซินและระยะเวลาในการย่อยเพิ่มขึ้น และเมื่อนำมาทวนสอบความแม่นยำของสมการจะเห็นได้ว่าทั้ง 3 ค่าตอบสนองมี Error (%) ต่ำ เนื่องจากค่าตอบสนองที่ได้จากการทดลองมีค่าใกล้เคียงกับการทำนาย โดยสภาวะที่เหมาะสมที่สุดในการผลิตคอลลาเจนไฮโดรไลเสตจากเท้าไก่ให้มีความสามารถในการต้านอนุมูลอิสระด้วยวิธี ABTS มากที่สุด คือการใช้เปปซิน 2.08% (w/w) ร่วมกับใช้ระยะเวลาในการย่อย 4.48 ชั่วโมงChicken feet contain high quality collagen and gelatin, which can produce proteins hydrolysate with bioactivity, resulting in higher value-added products. The objective of this study was to study the effect of pepsin content (0.02–5% w/w) in combination with digestion time (2–8 hours) to produce collagen hydrolysate from chicken feet with antioxidative activities through Response Surface Methodology (RSM). The experiment was Central Composite Design (CCD). The results showed that pepsin concentration and digestion time were related to the protein content and the hydrophobicity protein content. Increasing in pepsin concentration made protein content and hydrophobicity value of collagen hydrolysate higher. In addition, ABTS radical scavenging activity increased up to a certain level, and then, decreased when the pepsin concentration and digestion time increased more. To confirm the validity of the statistical model, all responses had low error value (%) because the observation values were close to the predicted values. Optimization by RSM showed that using 2.08% (w/w) pepsin with the digestion time of 4.48 hours could produce collagen hydrolysate with the highest ABTS radical scavenger activity

Optimization of extraction of phenolic compounds and antioxidants from passion fruit and rambutan seeds using response surface methodology

Passion fruit seed (PS) and rambutan seed (RS) contain sizable amounts of phenolic compounds (PCs) with bioactive compounds including antioxidant activity (AOA). The aim of this study was to optimize the extraction of PCs from PS and RS using response surface methodology (RSM). Preliminary results indicated that the solid to liquid (S-L) ratio of 1:40 (w/v) showed the highest yield (EY) for PS and RS, with values of 11.59 ± 0.08 and 14.55 ± 1.67 g/100 g samples, respectively. The S-L ratio of 1:30 (w/v) was selected as an economic logistic. The predicted response compared to experimental data for EY, EPC, DPPH, ABTS and FRAP of the extracts were 12.41 % (12.68 %), 715 (707), 85 (81), 539 (522) and 107 (160) mg GAE/100 g dry weight for RS and 13.68 % (14.41 %), 3141 (3235), 1327 (1434), 5793 (5564) and 1567 (1509) mg GAE/100 g dry weight for PS, respectively. The experimental data, including EY, EPC, and AOA, were fitted using a 2nd order polynomial equation. The statistical analysis revealed that ethanol concentration and extraction temperature significantly influenced PS (p < 0.001), whereas ethanol concentration primarily affected RS on the EY and EPC. The multiple regression analysis suggested that AOA of PS was significantly affected by linear, quadratic, and interaction of ethanol concentration, extraction time and temperature. Nonetheless, the AOA of RS was only affected by ethanol concentration. The best possible combinations for PS and RS were ethanol concentration 67 and 54 %, extraction temperature 94 and 63 °C, and extraction time 186 and 221 min, respectively, to obtain the maximum EY, extractable phenolic compounds (EPC) and AOA. The composite desirability values for the optimal conditions of PS and RS were 0.74 and 0.68, respectively. Optimal aqueous phenolic extracts from PS and RS could serve as sustainable food-grade ingredients and nutraceutical products

Optimization of microwave-assisted extraction of phenolic compounds and antioxidants from Careya sphaerica Roxb. flowers using response surface methodology

Careya sphaerica Roxb. flowers are good sources of phenolic compounds (PCs) with bioactive properties such as antioxidant activity. The objective of this study was to optimize the extraction parameters for microwave-assisted extraction (MAE) of PCs from C. sphaerica Roxb. flowers, utilizing response surface methodology (RSM) through a central composite design. The extraction of PCs was significantly (p < 0.05) impacted by process variables. The best possible combinations were microwave power (MP) 1000 W, solid to solvent (S-S) ratio 1:100 g: mL, ethanol concentration 40 % v/v, and extraction time 20 s to obtain the maximum extraction yield (EY), extractable phenolic compounds (EPC), DPPH and total flavonoid content (TFC). The maximum EY, EPC, DPPH, and TFC of 70.4 g, 33,504 mg GAE, 24,355 mg GAE and 13,115 mg CE, respectively were obtained per 100 g dry mass. The result suggests that MP and S-S ratio significantly (p < 0.05) affect the extraction of PCs and DPPH. All of the models applied to fit the responses were significant (p < 0.01) and suitable to represent the relationship between independent variables and responses. The study revealed the effectiveness of MAE using RSM for the extraction of PCs from C. sphaerica flowers

Impact of environmental storage conditions on properties and stability of a smart bilayer film

International audienceThis study aimed to investigate the behavior of smart bilayer films under various temperature and relative humidity (RH). Smart bilayer films were fabricated using sodium alginate with incorporated butterfly pea anthocyanin and agar containing catechin–lysozyme. Cellulose nanospheres were added at concentrations of 0% and 10% w/w of the film and subjected to test at 4 °C and 25 °C, considering different RHs (0%, 50%, and 80%). The results showed that RH had a greater impact on the mechanical properties than temperature, leading to a decrease in tensile strength and an increase in elongation at break with higher RH. The films displayed increased strength but reduced flexibility at low temperatures. Oxygen permeability was negatively affected by increasing RH, while water vapor barrier properties were better at 25 °C than at 4 °C. In terms of color stability, the temperature played a more important role, with both types of smart bilayer films retaining their color stability throughout 14-day storage at 4 °C, even maintaining their ability to change color with pH. However, the films stored at 25 °C exhibited lower color stability and showed potential for color change with varying pH levels, but with lower intensity. The findings of this study demonstrate the significant impact of temperature and RH on the functional properties of smart bilayer films, with and without the addition of cellulose nanospheres. Such smart bilayer films have great potential for various applications, particularly in food packaging, where maintaining color, mechanical, and barrier properties under varying environmental conditions is crucial

Using Anthocyanin Extracts from Butterfly Pea as pH Indicator for Intelligent Gelatin Film and Methylcellulose Film

International audienceAmong variety of intelligent food packaging, pH indicator packaging is becoming more popular, which can be made from synthetic and natural compounds. The search for natural pH indicator dyes that can be used in intelligent food packaging systems has recently focused on anthocyanins extracted from plants. Thus, this work aimed to develop and characterize an intelligent tag for pH indicator based on gelatin and methylcellulose-film with butterfly pea extract (BPE). The results showed that the colors of BPE solutions had a tendency to change from red to blue in a pH range of 4.0 to 8.0. The maximum absorption peak moved to a higher wavelength was observed at around 627 nm at pH 8.0 and shifted to 574 nm when the pH decreased to 5.0. After BPE was incorporated into the gelatin and methylcellulose-based films, the film’s properties were characterized. The color of the incorporated films changed from purple to blue and blue to green in buffers with pH ranging from 2.0 to 6.0 and 7.0 to 10.0, respectively. The incorporated gelatin-based film containing BPE showed a clearer response to pH variation and showed a high pigment releasing rate when immerse in buffer of pH 10. The incorporated methylcellulose-based film containing BPE had higher water solubility than that of gelatin-based film (p < 0.05), as well as improved mechanical properties and water vapor permeability (WVP). Therefore, it is possible to use the BPE (anthocyanins) as a visual pH indicator for food package