Search results

The purpose of this paper is to optimize a mixed juice made from Brazilian Cerrado fruits (cagaita, mangaba and marolo).

The juices were evaluated by rheological, physical, physicochemical, nutritional and sensory acceptance analyses. The mixture design is a widely used tool for product optimization, allowing the determination of factors, combinations and levels that provide best responses.

The results show that using mangaba pulp negatively contributed to juice acceptance, but resulted in the highest ascorbic acid content. The treatments produced using cagaita and marolo pulps presented a greater acceptance by consumers, and contributed to higher antioxidant activity and phenolic compounds content. The juice prepared with a mixture of equivalent quantities of the three fruits had the highest β-carotene and lycopene contents.

This research has shown that different fruit combinations can improve sensory and nutritional characteristics, adding value to the final product.

The processing of mixed juices could increase population access to the nutrients present in Brazilian Cerrado fruits, given that they are seasonal and perishable fruits.

In recent years, there has been an increase in the development of new food products based on Cerrado native fruits, however information on the chemical and nutritional characteristics, rheological behavior, and sensory attributes of the derivative products are still limited, resulting in a lack of scientific investments in this area. In addition, it is necessary to optimize the developed products to offer the consumer a unique product, combining the characteristics of two or more fruits, which adds value to the final product.

This study aims to describe the design and synthesis of two novel azo and imine chromophores-based dyes derived from two different aldehydes with intramolecular colour matching that are pH sensitive.

The visible absorption wavelength (λ_max) was extended when azo chromophore was included in imine-based systems. The dyed patterns created sophisticated colour-changing paper packaging sensors with pH-sensitive chromophores using alum as a mediator or mordant. Due to the tight adhesive bonding, the dyes on paper’s cellulose fibres could not be removed by ordinary water even at extremely high or low pH, which was confirmed by scanning electron microscopy analysis. The dyed patterns demonstrated an evident, sensitive and fast colour-changing mechanism with varying pH, from pale yellow to red for Dye-I and from pale yellow to brown-violet for Dye-II.

The λ_max for colour changing was recorded from 400 to 490 nm for Dye-I, whereas from 400 to 520 for Dye-II. The freshness judgement of food was checked using actual experiments with cooked crab spoilage, where the cooked crab was incubated at 37 ^oC for 6 h to see the noticeable colour change from yellow to brown-violet with Dye-II. The colour-changing mechanism was studied with Fourier transform infrared (FTIR) spectra at different pH, and thin layer chromatography, nuclear magnetic resonance and FTIR spectroscopy studied the desired structure formation of the dyes. Potential uses for smart packaging sensors include quickly detecting food freshness during transportation or right before consumption.

1. Two novel azo-imine dyes have been synthesized with a pH-responsive effect. 2. The pH-responsive mechanism was studied. 3. The study was supported by computational chemistry using density functional theory. 4. The obtained dyes were used to make pH-responsive sensors for seafood packaging to judge the freshness.

The purpose of this paper is to analyze and discuss the coupled effects of surface roughness and flow rheology for a homogeneous mixture of Newtonian base oil and power law fluids on the performance of elastohydrodynamic lubrication (EHL) circular contact problems.

The average flow model is adapted for the interaction of the flow rheology of lubricant and surface roughness. The average Reynolds type equation (ARTE) and the related flow factors (which describes the coupled effects of surface roughness and flow rheology of a mixture), the viscosity‐pressure and density‐pressure relations equations, the elastic deformation equation, and the force balance equation are then solved simultaneously. The multilevel multi‐integration algorithm and Gauss‐Seidel iteration method are utilized to calculate the film thickness and pressure distributions of the EHL circular contact problems effectively.

The effects of volume fraction, flow index of power law fluid, and surface roughness parameters (Peklenik number, standard deviation of composite surface roughness) on the film thickness and pressure distributions are discussed. The results show that the effects of surface roughness should be considered especially in EHL contact problems.

The EHL of circular contacts lubricating with mixture of two lubricants is first analyzed. The coupling effects of surface roughness and flow rheology of mixture (a Newtonian fluid and a power‐law fluid) on the EHL performance are first discussed in this paper.

Presents the view that higher solids clearcoats (more than 60 per cent solids) appear to be an attractive way for original equipment manufacture and refinish to meet European legislations as of 1998. New inventions in the area of low MW oligomers, alternative crosslinking mechanisms and rheology control agents appear to be capable of meeting the automotive and refinish performance levels. New developments in the area of surfactant free copolymerization open a new horizon to formulate waterborne clearcoats with excellent properties and appearance.