فصلنامه علوم و فنون بسته بندی
پیاپی 53 (بهار 1402)

In this study, optical properties of paper obtained from treatments 1, 2 and 4 weeks with the fungus Phanerochaete chrysosporium BKM - 1767 was evaluated and compared with control samples. After preparing fungal specimens, hornbeam chips three levels 1, 2 and 4 weeks under laboratory conditions were treated. To Chemical Mechanical Pulping from chips treated, 165oC baking temperature, cooking time 80 and 90 minutes and the percentage of sodium sulfite chemicals: 14, 18 and 22 percent compared to the cooking liquid to chips 7 to 1 was considered. In the case of brightness, the duration of treatment is also an important factor for increasing the effect of fungal treatment. The decrease in brightness in the 4-week treatment is significant. This point indicates that in the case of hornbeem, the effect of the fungal treatment on the brightness of the paper occurs only in the 4-week treatment. More increase of yellowness in 2 and 4 week treatments shows that the effectiveness of hornbeem in relation to the yellowness factor occurs with increasing the duration of fungal treatment. The opacity of the papers obtained from the treated wood chips has almost increased, but there is no significant difference between the opacity of the papers prepared in the control treatment and the opacity of the papers prepared in the fungal treatments.

The purpose of this research is the economic feasibility of producing wood plastic profiles from environmentally friendly materials (bagasse) in Khuzestan province. For this evaluation, industrial accounting principles were used. The total amount of investment for the annual production of 160,000 square meters of plastic wood is expected to amount to 72,491.5 million Tomans, which brings the following economic results internal rate of return (32.4%), return period of capital (26 months), production break-even point (16.88%), break-even sales (13,491.4 million Tomans), ratio of circulating capital to fixed capital (43.14%), fixed investment per capita (3376.3 million Tomans/person) and ratio of profit to capital (64.64%). The finished price of the product (295,365.75 Tomans for each square meter of wood plastic) shows that the construction of this factory, in addition to creating jobs and reducing the import of wood plastic, also prevents foreign exchange from leaving the country. Also, this plan has a suitable economic and financial justification.

Maintaining the quality and safety of food and thus maintaining people's health has been one of the most important concern of mankind since long time. One of the useful solutions to solve this problem is to switch to food packaging. Recognizing the nature of different foods, the emergence of availability and safe sources, and awareness of consumer expectations caused packaging to change from a simple cover to today's modern packaging with advanced functions. Making suitable packaging for each product, in addition to maintaining the quality and health of the product, can reduce the amount of food waste caused by unfavorable storage. Today, plastics are used more widely than other materials in the packaging industry and since these materials are derived from petroleum and in addition to consuming fossil fuels which are non-renewable resources, these remain in the environment for years and environmental concerns are increasing day by day. More about them, in this article, we review the different materials used in the packaging industry, their advantages and disadvantages, and general knowledge of new techniques and methods in food packaging. Also, special attention has been given to the investigation of novel packaging, which have more desirable features compared to the current common packaging in the country. In spite of these features such as better preservation of product quality and high marketability, in our country industrialization has not yet been carried out widely. In order to collect this article, from the September 2022 to the end of December 2022, a number of 196 articles were received and studied from the search engines MDPI, ScienceDirect, Google Scholar, CiteSeerx, Springer, Civilica and Scientific Information Database (SID), among which 108 sources was used.

Pickering emulsions stabilized by solid particles have attracted the attention of many researchers in recent years, because they provide better stability than surfactants for emulsions. Bacterial cellulose is a combination of cellulose nanofibers produced by some bacteria, so bacterial cellulose is one of the bottom-up synthesis methods. The unique nanofibril structure of bacterial cellulose offers excellent physical and mechanical properties, including high porosity, modulus of elasticity, and high crystallinity. Also, among solid stabilizers, cellulose nanocrystals are used as good materials in the preparation of Pickering emulsions, which have desirable properties such as nanostructure, high aspect ratio, biocompatibility, biodegradability, amphiphilic, chemical stability, low toxicity, and renewable. This article is a review of the researches conducted in the preparation of Pickering emulsions stabilized by bacterial cellulose and cellulose nanocrystals. At first, a summary of the preparation methods of bacterial cellulose and bacterial cellulose nanocrystals is discussed. Then, an overview on the production of Pickering emulsions, preparation methods and parameters affecting their stability are given in detail. The results of this review show that various parameters such as the concentration of nanocellulose particles, their surface charge, the use of surfactants, the type and concentration of oil used, pH, emulsion preparation temperature, ionic strength, the method used for preparing nanocelluloses and Pickering emulsions together affect the overall stability of the system. Finally, a perspective of the applications of this type of emulsions in the field of food packaging is presented.

Oxygen can reduce the quality and shelf life of some foods. The reason for the presence of oxygen in food packaging is mainly due to oxygen residues in the food, oxygen residues in the closed space, raw materials and damage to the containers during the packaging process. Basically, oxygen can cause food spoilage in various ways, including oxidative spoilage, which leads to a decrease in the quality of fats and fatty parts of food, oxidation of lipids, changes in the structure of proteins, vitamins and pigments, and providing suitable conditions for the growth of microorganisms and enzymatic browning. Researches show that various methods can be used to reduce the amount of this oxidative factor, including modified atmosphere packaging (MAP), vacuum packaging, and oxygen absorbers. In this review study, the mechanisms and applications of oxygen absorbers in the food industry and packaging of various food products were discussed. Studies show that the use of oxygen absorbers will have beneficial effects in increasing the quality and shelf life of various food products and reducing the wastage of food resources. Considering the importance of this issue, we can take steps towards the production, mass production and presentation of new formulations in the oxygen absorber production industry.

Today, food security is known as one of the dimensions of human security, so the lack of food security means the lack of security for that human society. In fact, food security is the cornerstone of a developed society and the first principle to maintain the health of society. In recent years, with the increase in population, on the one hand, the increase in demand for healthy food and on the other hand, the demand for food with high shelf life and good quality has become one of the challenges of the food industry. The first and most basic role of food packaging is to maintain the quality and safety of food and to reduce diseases transmitted through food, as well as to prevent product wastage and damage, and to protect the product from damage during transportation and storage. The important point is that the functional characteristics of the packaging should be suitable for use in the food industry. As a seasonal and perishable food product, food products cannot be directly available to the consumer for a long time. Therefore, the packaging industry plays an important role in ensuring the security, safety and health of communities, along with people's access to healthy food. In this article, the aim is to review the role of packaging on food safety, which has been addressed through a library review method.