Selecting the Packaging System for Liquid Foods Using an ANP Model

This paper provides a model to identify the most appropriate packaging system （i.e. the industrial process by which the product is hygienically coupled with the container） for different liquid foods. The model developed is grounded on the Analytic Network Process （ANP） methodology, a powerful and flexible tool used in decision making. To select the appropriate packaging system, the model takes into account several factors, including packaging material, cost, safety, performance （e.g., speed and accuracy）, plant reliability and flexibility, which may directly or indirectly affect the suitability of the process. Moreover, the chemical and physical properties of commercial liquid foods, and the packaging technology are included in the model as further variables to be considered for the final choice. We try to answer the following research questions： is a filling system appropriate for a given liquid food？ Is it compatible with a defined packaging technology？ When several filling systems are available for a given liquid food, how can the most appropriate one be selected？ The ease of application of the model and the robustness of the results provided have been tested on a sample of 59 commercial liquid foods, for which the model allowed to identify the most suitable packaging system, providing useful practical guidelines. The model was developed in close collaboration with a panel of experts, operating in the beverage bottling industry, and validated by the same experts; thus, the resulting tool is suitable for use as a decision support system by food and bottling industries.

A Modified Methodology to Evaluate Viscosity of Non-Newtonian Liquid Foods with a Flow Channel Instrument

Through experimental analysis of the liquid flows in a flow channel instrument, prompt evaluation of the physically defined viscosity of non-Newtonian liquid foods was investigated for development into a structurally simple and easy-to-use viscometer. For Newtonian and non-Newtonian test liquids, a relation between the friction coefficient and Reynolds number, which was dimensionless as derived from an expression of analysis as a gravity current, indicated a condition under which the flow in the instrument was laminar and under which an average shear rate was on the order of less than 1 s~. Prediction organized based on this empirical relation reproduced practically the flow curve determined for the liquid foods using a rotor type viscometer. Utilization of the channel instrument as a viscometer was formulated in terms of physical meanings of measurements such as the flow length and elapsed time.

Changes in electrical conductivity of liquid foods during ohmic heating

Ohmic heating is a food processing method in which alternating current(AC)went through a food sample and resulted in internal energy generation in foods.It is an alternative fast heating technique.Its principal advantage is the ability to rapidly and uniformly heat food materials of various densities.During ohmic heating,change in electrical conductivity was observed.The intensity of food materials’electrical conductivity or overall resistance critically controls ohmic heating rate.An ohmic heating set-up was prepared under this project.Tomato juice was heated(about 32℃ to 80℃)in a batch type ohmic heater at different voltage gradients in the range of 50-70 V/cm.It was statistically found that the voltage gradient had significant impact on conductivity and system performance coefficient(SPC)(P<0.05).It was concluded that the electrical conductivity values linearly increased with temperature.The SPCs of the system ranged between 0.779 and 0.943.The value of R2 of the linear model was greater than 0.98.

Determination of Sym-triazine Residues in Animal-derived Food by Liquid Chromatography-High Resolution Mass Spectrometry

[Objective]The research aimed to establish a liquid chromatography-high-resolution mass spectrometry for detecting residues of diclazuril,toltrazuril and its metabolites in animal-derived food.[Method]The samples were pre-treated by QuEChERS technology and detected by Exactive liquid chromatography-high resolution mass spectrometry.The liquid chromatography-high-resolution mass spectrometry for detecting the residues of diclazuril,toltrazuril,toltrazuril sulfone and toltrazuril sulfoxide in animal-derived food was established.[Result]Diclazuril,toltrazuril,toltrazuril sulfone and toltrazuril sulfoxide showed a good linear correlation in the range of 2.0-50.0μg/L（r^2〉0.99）.The average recoveries of these four compounds in bovine power at the spiked levels of 2,10 and 20μg/kg were 74.5%-90.1%,and the relative standard deviations（RSD）were 15.4%-17.5%.[Conclusion]This method was stable and reliable,and could be used to detect diclazuril,toltrazuril,toltrazuril sulfone and toltrazuril sulfoxide in animal-derived food.

How do groups of red imported fire ants （Hymenoptera： Formicidae） feed on a droplet of sugar water？

Many previous studies have focused on the foraging behaviors and strategies of the red imported fire ants, Solenopsis invicta Buren on solid food or granular bait; little attention has been paid to how liquid sugar is fed upon. In the present study, behavioral responses ofS. invicta to 25% sucrose water droplets were observed. Five foraging patterns were identified in S. invicta colonies under laboratory conditions： （i） no feeding, no sucrose water feeding was observed; （ii） surround feeding, ants surrounded and fed along the edge of the sucrose droplet; （iii） stacked feeding, ants stacked and fed along the edge of the sucrose droplet; （iv） droplet-break feeding, ants broke the liquid droplet and sucked sucrose water that spread on surface of the substance or soil particles previously transported by ants; and （v） cover feeding, whole surface of the sucrose droplet was covered by layers of feeding ants. This is the first time cover feeding in S. invicta has been reported, which obviously requires more ants compared to the other patterns. In addition, individual ants were tracked in videos under laboratory conditions, and behavioral repertoires that led to stacking, covering and droplet-breaking were identified and described. The field investigation showed that surround feeding was most frequently performed by S. invicta foragers; however, cover feeding was not observed under field conditions during this study. Both laboratory and field studies showed colony-level variations in sugar-water feeding.