E: Food Engineering & Physical Properties Beneficial Effects of Polyethylene Packages Containing Micrometer-Sized Silver Particles on the Quality and Shelf Life of Dried Barberry (Berberis vulgaris) N. Valipoor Motlagh, M.T. Hamed Mosavian, S.A. Mortazavi, and A. Tamizi Abstract: In this research, the effects of low-density polyethylene (LDPE) packages containing micrometer-sized silver particles (LDPE-Ag) on microbial and sensory factors of dried barberry were investigated in comparison with the pure LDPE packages. LDPE-Ag packages with 1% and 2% concentrations of silver particles statistically caused a decrease in the microbial growth of barberry, especially in the case of mold and total bacteria count, compared with the pure LDPE packages. The taste, aroma, appearance, and total acceptance were evaluated by trained panelists using the 9-point hedonic scale. This test showed improvement of all these factors in the samples related to packages containing 1% and 2% concentrations of silver particles in comparison with other samples. Keywords: antimicrobial effects, Barberry (Berberis vulgaris), low-density polyethylene package, micrometer-sized silver particle, sensory properties Practical Application: Low-density polyethylene package containing micrometer-sized silver particles had beneficial effects on the sensory and microbial quality of barberry when compared with normal packing material. Introduction Seedless barberries have food usages and drug benefits. Apart from using dry barberry as seasoning of foods, barberry is used in the production of some food stuffs, such as sauce, jelly, candy, concentrate, juice, gassy drinks, jam, marmalade, barberry sherbet, barberry powder, polaki, honey candy, and barberry fruit roll. In addition to the applications of barberry in traditional medicine, antihistaminic and anticholinergic (Shamsa and others 1999), an- tioxidant (Tomosaka and others 2008; Qadir and others 2009), anticancer (Duke 2002; Ho and others 2009; Qadir and others 2009), antigout, antiphlogosis, antiacne, and antispasm properties (Kafi and Balendari 2002) of this plant have been proved. More- over, barberry decreases blood sugar and blood cholesterol (Kafi and Balendari 2002; Schmandke 2007). Water and enzyme activities, microbial growth, and change in the pigment color are some of the most important factors that affect the quality of barberry. One problem related to these dam- aging factors is barberry packaging (Kafi and Balendari 2002). Nowadays, more attention is paid to the nanocomposite pack- ages than other ones. Nanocomposites improve the mechanical, thermal, and oxidation stability and also the barrier properties of MS 20101231 Submitted 12/26/2010, Accepted 10/11/2011. Authors Motlagh and Mosavian are with Chemical Engineering Dept., Ferdowsi Univ. of Mashhad, Mashhad, Iran. Author Mortazavi is with Food Science and Technology Dept., Ferdowsi Univ. of Mashhad, Mashhad, Iran. Author Tamizi is with Birjand Univ. of Medical Sciences, Birjand, Iran. Direct inquiries to author Motlagh (E-mail: nasservalipoormotlagh@gmail.com). polymers (Azeredo 2009; Arora and Padua 2010; Mahalik and Nambiar 2010). Meanwhile, biodegradable biopolymers as polysaccharides, proteins and so on are expected to gradually replace poorly degradable plastics but these materials, generally have serious disadvantages, such as poor mechanical characteristics and high water permeability. Combination of biopolymers with some nanoparticles seems to solve this problem (Popov and others 2010). In addition to the mentioned properties, some nanocom- posites containing antimicrobial agents have antimicrobial prop- erties. Different types of metal antimicrobial agents, like copper, zinc, titanium dioxide, magnesium, gold, and silver are available; however, silver particles have proved to be the most effective. This is due to their antimicrobial activity against a wide range of mi- croorganisms. Micrometer-sized silver particles have larger surface area available for interaction with microbial cells in comparison with larger particles. This improves their antimicrobial property. Among antibacterial metals, silver is a safe and broad-spectrum antibacterial agent (Gong and others 2007; Azeredo 2009; Chudasama and others 2009; Rai and others 2009). It should be noted that particles of 50 nm can penetrate to cells, of 70 nm to lungs, and of 30 nm even to blood and brain cells (Chau and others 2007; Mortimer and others 2008). Thus, they can migrate from lungs to the circulatory system, spread over the whole body, and further enter some organs (liver, spleen, marrow, heart, brain, and so on) (Popov and others 2010). Scientific Committee on Emerging and Newly Identified Health Risk (2006) reported that expected consumer exposure remains low as long as the inert sil- ver nanoparticles (Ag-NPs) are bound in the packaging materials or in the coatings on surfaces of packaging materials and food preparation devices. A scientific opinion of European Food Safety C  2011 Institute of Food Technologists R  E2 Journal of Food Science  Vol. 71, Nr. 1, 2012 doi: 10.1111/j.1750-3841.2011.02497.x Further reproduction without permission is prohibited