Experimental study on mechanical properties of pumpkin tissue

Purpose: The purpose of this study was to calculate mechanical properties of tough skinned vegetables as a part of Finite Element Modelling (FEM) and simulation of tissue damage during mechanical peeling of tough skinned vegetables. Design/methodology: There are some previous studies on mechanical properties of fruits and vegetables however, behaviour of tissue under different processing operations will be different. In this study indentation test was performed on Peel, Flesh and Unpeeled samples of pumpkin as a tough skinned vegetable. Additionally, the test performed in three different loading rates for peel: 1.25, 10, 20 mm/min and 20 mm/min for flesh and unpeeled samples respectively. The spherical end indenter with 8mm diameter used for the experimental tests. Samples prepare from defect free and ripped pumpkin purchased from local shops in Brisbane, Australia. Humidity and temperature were 20-55% and 20-250C respectively. Findings: Consequently, force deformation and stress and strain of samples were calculated and shown in presented figures. Relative contribution (%) of skin to different mechanical properties is computed and compared with data available from literature. According the results, peel samples had the highest value of rupture force (291N) and as well as highest value of firmness (1411Nm-1). Research limitations/implications: The proposed study focused on one type of tough skinned vegetables and one variety of pumpkin however, more tests will give better understandings of behaviours of tissue. Additionally, the behaviours of peel, unpeeled and flesh samples in different speed of loading will provide more details of tissue damages during mechanical loading. Originality/value: Mechanical properties of pumpkin tissue calculated using the results of indentation test, specifically the behaviours of peel, flesh and unpeeled samples were explored which is a new approach in Finite Element Modelling (FEM) of food processes. Keywords: Finite Element Modelling (FEM), relative contribution, firmness, toughness and rupture force

Investigating Antimicrobial Characteristics/Advantages of Australian Wood Species for Use in Food Packaging - A Feasibility Study

The antimicrobial characteristics of Australian commercial timber species were studied using a direct screening method and two different microorganisms. The effectiveness of timber samples was compared with plastic and paper samples during an incubation period of 24 h at 37 °C. The initial data with E. coli and S. aureus showed no difference in performance between the plastic and paper samples and the softwood samples tested. Hardwood samples, however, showed an inhibition zone when tested with S. Aureus. The data showed similar trends of inhibition zones developed for sterilised and non-sterilised samples of spotted gum and shining gum species. The observed data showed promising antimicrobial characteristics for both veneer and solid samples of hardwood species. Further studies investigating the type of extractives, their role in antimicrobial characteristics and differences in the type of surface exposed to the microbial contamination from the point of view of timber’s anatomical properties are proposed

A Review of Traceability Systems in the Timber Industry

Wood, as a most important renewable and sustainable material source, has been widely used in many fields and our daily life for thousands of years. It constructs a bridge between tradition and modernity. During the manufacturing process, new materials, new connections, and new adhesives, as well as better logistics, will influence the wooden products quality, manufacturing, and transfer efficiency. In conclusion, they will influence the whole wood industry. The cascade utilization of wood in different wooden unit size scales, including macro, micro, even nanoscale. It can also be combined with various polymer systems to obtain composites with incredible performances. The aim of this book is to present the conventional, present and future advanced functional wooden composites, from traditional wood timber, to currently popular wood-based panels, wood-bioenergy, wood-carbon stock, wood-biodiversity of nature value, including light-weight wooden materials, use of alternative fast-growing species/recycled wood, a new adapted process to hardwoods and softwood, and many others. In addition, the most recent research achievements of super wood products with different functionality using advanced and novel techniques in high added value fields will also be covered

Effect of Alternate Drying Techniques on Cross-Laminated Timber after Exposure to Free-Water Wetting

Cross-laminated timber (CLT) panels are commonly used in mass-timber multistorey constructions due to their prefabrication, construction flexibility, environmental credentials and weight-to-strength ratio advantages compared to competing building materials. However, the long-term durability and service life of these mass timber panels require further understanding of their performance when exposed to free water. Wetting and drying trials were conducted by exposing Radiata pine (Pinus radiata) CLT sections to either free water (pooling on a single surface) or submerged water (all directions exposed) saturation, followed by either ambient or fan drying. The panels exposed to water pooling only reached MC above the FSP up to 40 mm of the panel depth. For submerged panels, the MC reached values above the fibre saturation point (FSP) at depths of 30 to 40 mm penetration on both panel faces. When comparing the ambient and fan-drying panel sections over the same time period, a less uniform MC profile was observed for the ambient drying, whereas the fan-dried panels fell below the FSP faster and with a more consistent MC profile. A complementary study was conducted on a standalone 3.0 × 3.0 m CLT room, where the room was wetted during a simulated pipe burst event. The moisture monitoring of wall and floor panels during fan drying of the room showed that an MC reduction from an excess of 40% to below 20% could be reached in less than 96 h for the panels’ surface; however, the middle sections of the panels dried slower than the surface sections. The CLT structure fan drying required a longer drying time than the CLT sections tested due to the closed sections (overlaps and connected faces) and a lower rate of airflow. The study of drying CLT sections highlighted the product reaching and maintaining MC higher than FSP points and the need for further drying applied to minimise long-term decay development. Further study is recommended to investigate the effects of closed sections (connected faces) and the duration of drying needed for semi-finished and finished buildings

Cardioprotective Effects of Coenzyme Q10 Supplementation on Patients with ST-Segment Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention

Background: We assessed the potential efficacy of Coenzyme Q10 (CoQ10) in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI). Methods: Seventy STEMI patients who presented ≤12 hours after the onset of symptoms and were scheduled for PPCI were randomly assigned to the standard treatments plus CoQ10 or placebo. In the intervention group, CoQ10, as an oral capsule at a dose of 400 mg, was loaded immediately before PPCI and continued at 200 mg twice daily for 28 days. The control group received a matching placebo, similarly. The study endpoints were the proportion of patients with complete myocardial reperfusion, defined as thrombolysis in myocardial infarction (TIMI) flow and myocardial blush grade (MBG) 3 at the end of PPCI, the proportion of patients with complete ST-segment elevation resolution (≥70%) assessed 60 minutes after PPCI, the plasma levels of creatine kinase myocardial band isoenzyme (CK-MB) and troponin I (TnI) at 12, 24, 48, and 72 hours after PPCI, and left ventricular ejection fraction (LVEF) at day 28. Results: The study groups were comparable regarding baseline clinical and procedural characteristics. The proportion of patients with TIMI flow grade 3, MBG 3, and complete ST resolution after completion of PPCI was similar between the groups. Whereas at all-time points after PPCI (12, 24, 48, and 72 hours), the plasma levels of CK-MB and TnI were significantly lower in the CoQ10 group than in the control group. Further, at day 28, CoQ10-treated patients exhibited better LVEF than placebo-treated patients, and the proportion of patients with LVEF less than 50% was lower in the intervention group than in the control group. Conclusion: Our study provided evidence that CoQ10 supplementation might reduce myocardial ischemia-reperfusion injury after PPCI and help to preserve left ventricular function. However, further studies are required to validate these results

Mechanical behaviours of pumpkin peel under compression test

Mechanical damages such as bruising, collision and impact during food processing stages diminish quality and quantity of productions as well as efficiency of operations. Studying mechanical characteristics of food materials will help to enhance current industrial practices. Mechanical properties of fruits and vegetables describe how these materials behave under loading in real industrial operations. Optimizing and designing more efficient equipments require accurate and precise information of tissue behaviours. FE modelling of food industrial processes is an effective method of studying interrelation of variables during mechanical operation. In this study, empirical investigation has been done on mechanical properties of pumpkin peel. The test was a part of FE modelling and simulation of mechanical peeling stage of tough skinned vegetables. The compression test has been conducted on Jap variety of pumpkin. Additionally, stress strain curve, bio-yield and toughness of pumpkin skin have been calculated. The required energy for reaching bio-yield point was 493.75, 507.71 and 451.71 N.mm for 1.25, 10 and 20 mm/min loading speed respectively. Average value of force in bio-yield point for pumpkin peel was 310 N

Study of tissue damage during mechanical peeling of tough skinned vegetables

Peeling is an essential phase of post harvesting and processing industry; however the undesirable losses and waste rate that occur during peeling stage are always the main concern of food processing sector. There are three methods of peeling fruits and vegetables including mechanical, chemical and thermal, depending on the class and type of fruit. By comparison, the mechanical method is the most preferred; this method keeps edible portions of produce fresh and creates less damage. Obviously reducing material losses and increasing the quality of the process has a direct effect on the whole efficiency of food processing industry which needs more study on technological aspects of this industrial segment. In order to enhance the effectiveness of food industrial practices it is essential to have a clear understanding of material properties and behaviour of tissues under industrial processes. This paper presents the scheme of research that seeks to examine tissue damage of tough skinned vegetables under mechanical peeling process by developing a novel FE model of the process using explicit dynamic finite element analysis approach. In the proposed study a nonlinear model which will be capable of simulating the peeling process specifically, will be developed. It is expected that unavailable information such as cutting force, maximum shearing force, shear strength, tensile strength and rupture stress will be quantified using the new FEA model. The outcomes will be used to optimize and improve the current mechanical peeling methods of this class of vegetables and thereby enhance the overall effectiveness of processing operations. Presented paper aims to review available literature and previous works have been done in this area of research and identify current gap in modelling and simulation of food processes