Valorization of Rice Straw into Cellulose Microfibers for the Reinforcement of Thermoplastic Corn Starch Films  
[PERSON]  
1 Research Institute of Food Engineering for Development (IIAD), Universitat Politecnica de Valencia (UPV), 46022 Valencia, Spain; [PERSON]DDRESS] (C.L.F.A. ); [PERSON]@upves (S.T.-G.); [PERSON]@tal.upves (C.G.-M.); [EMAIL_ADDRESS] (A.C.)  
[PERSON]  
1 Research Institute of Food Engineering for Development (IIAD), Universitat Politecnica de Valencia (UPV), 46022 Valencia, Spain; [PERSON]DDRESS] (C.L.F.A. ); [PERSON]@upves (S.T.-G.); [PERSON]@tal.upves (C.G.-M.); chchiralt@tal.upves (A.C.)  
[PERSON]  
1 Research Institute of Food Engineering for Development (IIAD), Universitat Politecnica de Valencia (UPV), 46022 Valencia, Spain; [PERSON]DDRESS] (C.L.F.A. ); [PERSON]@upves (S.T.-G.); [PERSON]@tal.upves (C.G.-M.); chchiralt@tal.upves (A.C.)  
[PERSON]  
1 Research Institute of Food Engineering for Development (IIAD), Universitat Politecnica de Valencia (UPV), 46022 Valencia, Spain; [PERSON]DDRESS] (C.L.F.A. ); [PERSON]@upves (S.T.-G.); [PERSON]@tal.upves (C.G.-M.); chchiralt@tal.upves (A.C.)  
2  
Footnote 1: email: {c.c.f.c.f.c.c.f.c.f.c.c.f.c.f.c.f.c.f.c.f.c.f.c.f.c.f.c.f.c.f.c.f.c.f.c.f.c.f.c.f.c.c. and excellent mechanical properties [12]. Thus, these lignocellulosic fractions can be used as reinforcing fillers of biopolymers in green composites for food packaging applications. After harvesting the rice grain (_Oryza sativa_ L.), one of the most important primary crops, large quantities of rice straw (RS) are obtained worldwide. In fact, the annual rice production is estimated at 782 million tons and 1 kg of rice grain yields approximately 1.5 kg of RS [13; 14]. Generally, RS is directly burned in the paddies, which intensifies air pollution and damages soil feasibility and population health. Therefore, constant efforts are currently being made to propose different management approaches for this biomass waste [14; 15]. Since RS is a lignocellulosic material that is composed of approximately 39% cellulose, 20% lignin, 23% hemicellulose, and 15% ashes, this waste derived biomass can be used to obtain several renewable added-value materials with interesting properties [16]. Among the most practical alternatives, RS can be valorized into CMFs by different extraction methods. Typically, CMFs from RS has a strong crystalline structure and low density, which can be used as reinforcing agent in biodegradable polymers instead to petroleum derived plastics [2; 17]. Starch is a semicrystalline biopolymer consisting of linear and branched chains of D-glucopyranose units known as amylose and amylopectin, respectively [18]. The proportion of both constituents varies according to the source, from which the most common are cassava, maize, sweet potato, rice, oats, and peas [19; 20]. Starch is widely investigated for several applications due to its renewability, biodegradability, low cost, availability, and biocompatibility [21; 22; 23]. In its native state, starch can be processed with a plasticizer in an extruder at temperatures between 140 and 160 \({}^{\circ}\)C and high pressure, giving rise to an amorphous material with thermoplastic behavior [21]. Although thermoplastic starch (TPS) films are excellent barriers to lipids, oxygen, and carbon dioxide, their use in food packaging is still limited since the barrier and mechanical properties are highly dependent on moisture content [18; 24; 25]. To overcome these shortcomings, the preparation of biodegradable TPS films reinforced with CMFs obtained from agro-industrial wastes is an interesting alternative. Previous studies have reported that the incorporation of cellulosic materials in TPS-based green composite films exhibited enhanced mechanical properties [20; 26], water vapor [27] and oxygen gas barrier [22], and thermal stability [28].