Search results for "Cold"

Manufacturing and characterization of Al matrix composites with nano reinforcements via cold spraying

2019

This study aims at developing new routes for manufacturing Al matrix composites (AMCs) strengthened with nano reinforcements by solid-state cold spraying (CS) process. Three different AMCs including CNTs/Al, TiB2/AlSi10Mg and TiB2/7075Al were successfully fabricated by CS of the composite powders prepared using different approaches. The microstructure evolution of as-sprayed composite samples was investigated by means of different characterization methods like X-ray diffraction (XRD), scanning (SEM) and transmission electron microscopy (TEM) and electron backscatter diffraction (SEM/EBSD). The adhesion strength, tribological behaviour, corrosion properties as well as the mechanical performa…

Effect of cold drawing on the antimicrobial and physical properties of PCL/CHX monofilaments

2012

Diversification de la production de l’aquaculture sicilienne à travers la production de filets de maigre (Argyrosmus regius) fumés: de la caractérisa…

2016

Within the Work-package 5 «Valorisation de l'image des produits aquacoles», activity 5.3 «Innovation en vue de valoriser les produits aquacoles», a cold smoking protocol was applied on meagre, Argyrosomus regius fillets, an emerging species for Sicilian aquaculture. Nutritional characterization and consumer tests were conducted on three different scales (laboratory, restaurant, seafood exhibition), in order to record the level of consumers’ satisfaction towards this new product. The results obtained indicate that the applied cold smoking protocol yielded a product with nutritional value comparable to fresh fillets. The low level of lipids and the high content of polyunsaturated fatty acids …

Physical and chemical changes in minimally processed green asparagus during cold-storage

2007

The purpose of this research is to study effects of an innovative packaging method on the shelf-life of minimally processed green asparagus. The physical-chemical parameters analyzed (weight loss, colour, texture, chlorophyll and citric acid), and monitored by untrained panellists during the cold storage period at 6 degrees C, showed that pairing of a semi-permeable film with an adsorbent material and immersion in ascorbic acid solution were able to extend the shelf-life of green asparagus. Also, on the basis of the results obtained, a study of the chlorophyll and toughness degradation kinetics of green asparagus was conducted during cold storage. These data showed the toughening of asparag…

DEGRADATIVE ENZYMATIC ACTIVITIES IN FRESH-CUT BLOOD ORANGE SLICES DURING CHILLED STORED

2009

Summary Blood-orange fruits are suitable to fresh-cut fruit production because of their chemical compositions. Nevertheless, the main limitation of using freshly cut oranges is their susceptibility to juiciness loss and ascorbic acid degradation because of enzymatic alterations. The aim of this work is: to identify some of the enzymes causing the qualitative decay in blood-orange slices during 15 days of chilled storage (at 4 ± 0.5 °C and 85% RH); to investigate the susceptibility to the previous alterations of five blood-orange clones (Moro nucellare, Sanguinello nucellare, Tarocco arcimusa, Tarocco gallo and Tarocco meli) to select the most suitable one for fresh-cut production. The enzym…

SALINITY EFFECTS ON ENZYMATIC BROWNING AND ANTIOXIDANT CAPACITY OF FRESH-CUT BABY ROMAINE LETTUCE (LACTUCA SATIVA L. CV. DUENDE)

2010

Abstract Enzymatic browning is a main problem encountered in minimal processing and further storage of leafy vegetables, leading to shorter shelf-life of products. Changes in the two oxidative activities, polyphenol oxidase (PPO) and peroxidase (POD), as well as in total phenolic content, colour parameters and antioxidant capacity (assayed with ORAC method), were monitored during 10 days of storage at 4 °C of minimally processed baby Romaine lettuce ( Lactuca sativa L. cv. Duende) cultivated under three different salinity conditions (2.8, 3.8 and 4.8 dS m −1 ), in order to determine the most suitable condition for further processing. Increasing levels of salinity reduced both oxidases activ…

Effect of Vibration on the Quality of Strawberry Fruits Caused by Simulated Transport

2015

Mechanical damage of agricultural products is one of the main problems in the harvest and postharvest chain due to the large economic loss that the shelf life reduction could generate. Measurements of change in the chemical components of highly perishable products and microbial growth under different static and dynamic loads is the first step in the development of intelligent logistic units that could help in predicting the residual shelf life in order to minimize losses along the supply chain. In our research, the effects of vibration along the supply chain of a case study were analyzed on strawberry (Fragaria × ananassa) and woodland strawberry (Fragaria vesca) in terms of microbiological…

Changes of morphogenic competence in mature Pinus sylvestris L. buds in vitro.

2002

The effects of season and cold storage on morphogenic competence in mature Pinus sylvestris buds were investigated. Peroxidase and polyphenol oxidase activity were measured as markers of oxidative metabolism. No growth in vitro was observed on explants detached from the end of January until the beginning of March. Brachioblasts, each with a couple of needles, formed on 11 % of the buds without macrostrobili that were detached in early April and introduced immediately into culture. Of the explants detached in late July, 15 % formed shoots with brachioblasts and needles. The lowest activity of peroxidase and polyphenol oxidase in pine buds was observed from the end of April until the beginnin…

Effects of passive and active modified atmosphere packaging conditions on quality parameters of minimally processed table grapes during cold storage

2015

BACKGROUND: Table grape is a non-climacteric berry, sensitive to water loss and gray mold during postharvest storage. OBJECTIVE: To assess the effect of passive and active modified atmosphere packaging on quality parameters of minimally processed table grapes. METHODS: 'Red Globe' minimally processed table grapes were dipped in a sodium hypochlorite solution and irradiated with ultraviolet-C, before being packaged in a rigid polypropylene boxes, sealed with a micro perforated polypropylene film (PP) or a continuous polyethylene film, with: a) 5% O2 + 15% CO2 + 80% N (PET1); b) 20% CO2 + air (PET2). Samples were stored at 5°C for 21 days plus and additional 6-day period at 20°C to simulate s…

Damage and fracture study of cold extrusion dies

2004

Abstract In the present paper die fracture in cold extrusion was investigated considering a few different die reduction zone geometries. A former finite element method (FEM) analysis of the process was developed to obtain the contact pressure distribution at the workpiece–die interface for each of the investigated geometries; subsequently a stress and strain analysis utilizing the BEM code Franc3D was carried out, with the aim to evaluate the crack propagation at each loading cycle, i.e. at each extrusion process. In this way the die life for each of the investigated extrusion die geometries was compared utilizing the Paris law and the values assumed by the stress concentration coefficient …