**8. Novel packaging materials and their environmental consequences**

Novel packaging system evolved to cater for food consumers' dynamic change in tastes of food products occasioned by change in life styles that increasingly inclined them to demand for mildly processed and convenience food products with enhanced shelf-life. Such packaging designed with innovation or application of new ideas and knowledge in packaging process/methods; according to Majid et al. [54]; 'act by prolonging the shelf life, enhancing or maintaining the quality, providing indication and to regulate freshness of food product'. The literature mentioned the types novel packaging and materials in involved to include active packaging, intelligent packaging, bioactive packaging, eco-friendly packaging, and others [40]. Apart from the reasons already adduced for evolution of novel packaging system, the literature mentioned solving the problems of environmental pollution/destructions associated with the traditional and conventional packaging systems as part of the reasons. For instance, Salgado et al. [55] reported the enormous environmental problems caused by increasing use of plastics in place of other materials in the conventional food packaging systems; because the plastics being mostly products of petroleum, are non-degradable. The need to protect the environment and promote economic values of food packaging resulted into researches and subsequent discovery of materials that are biodegradable and renewable and hence, are eco-friendly. This statement is in agreement with the observation of Cazon et al. [56] that 'biodegradable and renewable materials represent a great alternative to protect the environment and give economic values to underutilized products and industrial waste materials'. The use of bioplastics, defined as 'plastic materials that are either biobased (partly or entirely) or biodegradable or feature both properties' [55], predominates in novel packaging system. Whereas biobased indicates that the materials sourced from biomass, biodegradable shows that it can be biologically degraded to the constituent substances such as water, carbon dioxide, methane, basic elements, and biomass by living organisms that are available in the environment [57]. Salgado et al. [55] further elucidated on the classes bioplastics and mentioned three types which includes; (i) 'biobased but nonbiodegradable plastics such as bio-polyethylene (Bio-PE), bio-polyamide (Bio-PA), bio-polyethylene terephthalate (Bio-PET), bio-polytrimethylene terephthalate (Bio-PTT), biopolyurethanes (Bio-PU), biopolypropylene (Bio-PP); (ii) plastics that are biodegradable and based on fossil resources, such as poly(butylene adipateco-terephthalate) (PBAT), poly(butylene succinate-co-butylene adipate) (PBSA), polyvinyl alcohol (PVA), polyglycolic acid (PGA), polycaprolactone (PCL); and (iii) plastics that are both biobased and biodegradable'. Petersen et al., [57] further stated that the 'last group include: polymers directly extracted from biomass such as polysaccharides (e.g., starch, cellulose, chitin, etc.) and proteins (e.g., collagen, gelatin, casein, whey, soy protein, zein, wheat gluten, etc.); whose further modification can produce additional valuable biobased materials such as cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cellulose nitrate, regenerated cellulose, carboxymethyl cellulose, lignocellulosic products, chitosan, etc.); polymers produced by chemical synthesis using renewable biobased monomers, such as polylactic acid (PLA), a bio-polyester polymerized from lactic acid monomers produced by fermentation of carbohydrate feedstock; and polymers produced by microorganisms or genetically modified bacteria such as polyhydroxyalkonoates (PHA) like polyhydroxybutyrate (PHB) and polyhydroxyvalerate (PHV) and bacterial cellulose'. Khoo et al. [58] compared environmental impacts of bioplastic packaging materials with those of the conventional plastics and stated that bioplastics are eco-friendlier. And Salgado et al. [55] threw more light on the forgoing by reporting that 'biobased plastics, which are generally drop-in products for their petroleum-based counterparts, are adequate for material recycling and/or energy recovery, whereas biodegradable plastics are intended for organic recycling'. Also, the report of European Bioplastics Organization cited by Salgado [55] indicated that bioplastics minimizes their impacts on environment through proper bio-wastes' management, separation and collection which eventually produces valuable compost manures usable in growing crops that initiate the life cycle.
