scholarly journals Assessment and determination of lyoprotectant for survival of freeze-dried Lactobacillus rhamnosus

2016 ◽  
Vol 20 (1) ◽  
pp. 105-113
Author(s):  
Zongcheng Miao ◽  
Yang Zhao ◽  
Xiaoping Huo

Abstract Currently research of lactic acid bacteria focus primarily on the functional probiotics, which are major beneficial biota in the gastrointestinal tract, have been industrial manufactured. Probiotics confer health benefits on the host need adequate amounts. However, the absence of data makes it difficult to ensure the maintenance biological activities and population of probiotic. In this research, a fractional factorial design and steepest ascent experiment were used to analyze the influence of lyoprotectant as carbohydrates, prebiotics and amino acids on the survival of the probiotic Lactobacillus rhamnosus. The results indicated a maximum survival rate and population of viable bacteria of L. rhamnosus to be 55.84 % and 1.60 ×1011 CFU/g after freeze-dried by using a combination of 10 g/100mL Sucrose, 2.5 g/100mL Isomaltooligosaccharide, 12 g/100mL Hydroxyproline. To a large extent, the survival and viability were dependent on the cryoprotectant used and make probiotics more attractive from a practical application in industrial viewpoint.

2017 ◽  
Vol 15 (1) ◽  
pp. 293-298
Author(s):  
Pakinaz Y. Khashaba ◽  
Hassan Refat H. Ali ◽  
Mohamed M. El-Wekil

AbstractA simple, rapid, cost-effective, and sensitive TLC-spectrodensitometric method for simultaneous determination of esomeprazole and domperidone was developed and tested in human plasma. Ethyl acetate: methanol: benzene: acetonitrile (5: 4: 8: 3, v/v/v/v) mobile phase was used for separation on TLC plates detected at 286 nm. The linearity ranges were 5-1200 and 2-600 ng/ spot for esomeprazole and domperidone, and limits of detection were 1.73 and 0.59 ng/spot. The effects of four variables affecting Rf were evaluated by fractional factorial design. The benzene volume and saturation time had significant effects.


2008 ◽  
Vol 3 (1) ◽  
pp. 10-29 ◽  
Author(s):  
Roberta Veale ◽  
Pascale Quester

AbstractThe purpose of the study was to investigate the respective influences of price and country of origin as extrinsic cues on consumer evaluations of wine quality when all intrinsic cues are experienced through sensory perception. Taste testing experiments were conducted (N = 263) using Chardonnay as the test product in a 3 (country of origin, COO) × 3 (price) × 3 (acid level) conjoint analysis fractional factorial design. Price and COO were both found to be more important contributors to perception of wine quality than taste. Reliance on extrinsic cues was found to remain extremely robust even when all intrinsic cues were available through sensory experience for respondent evaluation. The research demonstrated that even when evaluating a product through consumption, consumer belief in the price/value schema dominates quality assessment. These findings mean that marketers cannot assume that intrinsic product attributes, even when experienced, will be weighted and interpreted accurately by consumers. The research significantly advances our understanding of consumers' use of extrinsic cues (price and COO specifically), and their respective influence in their determination of both expected and experienced quality. (JEL Classification: Q11, D12, M31)


Author(s):  
SF Wang ◽  
JH Zhang ◽  
ZG Liu ◽  
XW Zhang ◽  
J Hong ◽  
...  

Riveted joints are extensively adopted in designing aircraft structures. Riveting implies a squeezing process of the rivet with large plastic deformations to form the driven rivet head. The driven rivet head dimensions (height H, diameter D) depend on riveting force ( X1), rivet length and diameter tolerance ( X2 and X3), as well as rivet hole tolerance ( X4). Incorrect selection in these parameters could induce the excessive stress concentration that results in initial crack and also results in improper rivet head deformation leading to loose rivet. The present research is conducted on a MS2047AD6-6 rivet and 2.286 mm thick aluminum alloy sheets and mainly focuses on the design of riveting parameters X1, X2, X3, and X4 using the proposed three-step statistical experiment designs including fractional factorial design, steepest ascent design, and central composite design while satisfying the quality requirements for driven rivet head dimensions ( H, D) mentioned in Standard Aircraft Handbook. Fractional factorial design is used to evaluate the impact of riveting parameters X1, X2, X3, and X4 on H and D. Based on the effective ranges of the significant riveting parameters obtained from steepest ascent design, a five-level central composite design is proposed to derive the statistical relations between H, D and the significant riveting parameters, and the statistical models are used to find the feasible region resulting from the combination of the significant riveting parameters while satisfying the quality requirements for H and D. Finally, the feasible ranges of X1, X2, X3, and X4, namely [16,470 N 22,730 N], [−0.1491 mm 0.3891 mm], [−0.0466 mm 0.1216 mm], and [−0.0375 mm 0.2125 mm], are determined from the perspective of adjustable accuracy of X1 and that of the manufacturability for X2, X3, and X4. It implies that any combination of X1, X2, X3, and X4 that falls within this feasible region can result in a good quality riveted joins, namely that the quality requirements for the driven riveting head dimension ( H, D) can be satisfied.


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