Pineapple crown leaf fiber (PCLF) is one of the major biomass wastes from pineapple processing plants. It consists mostly of carbohydrate polymers, such as cellulose, hemicellulose, and lignin. It can be further processed to form a more valuable and widely used nanocrystalline cellulose (NCC). This study investigates the effect of hydrolysis time on the properties of the produced NCC. The acid hydrolysis was conducted using 1 M of sulfuric acid at hydrolysis times of 1–3 h. The resulting NCCs were then characterized by their morphology, functional groups, crystallinity, thermal stability, elemental composition, and production yield. The results show that the NCC products had a rod-like particle structure and possessed a strong cellulose crystalline structure typically found in agricultural fiber-based cellulose. The highest NCC yield was obtained at 79.37% for one hour of hydrolysis. This NCC also displayed a higher decomposition temperature of 176.98 °C. The overall findings suggest that PCLF-derived NCC has attractive properties for a variety of applications.

Purpose: This study aims to investigate how social capital (e.g. cognitive and relational) influences students’ trust (e.g. cognitive and affective) as mediator variables, affecting students’ information sharing activity on Facebook. Design/methodology/approach: The sample consists of 398 valid participants obtained through an online survey and using structural equation modeling (SEM) to test the research hypotheses. Findings: The empirical results indicate that social capital has significant and positive effects on students’ trust (e.g. cognitive and affective-based trust), also mediator variables. Furthermore, the mediator variables partially mediate social capital and information sharing based on the concept of cognition-affection-behavior (CAB). Research limitations/implications: This study was limited to Indonesian students. Therefore, future study is needed to analyze across cultures and regions. It can help practitioners, regulators and researchers to observe the dynamic behavior on the impact of social capital on social media users’ activities. Practical implications: Education stakeholders (e.g. lecturers and teachers) can identify the students’ goal and rational concerns to improve their social capital and trust to share information. The government as a regulator needs to support students’ activities on social media to provide updated information regarding economic and social conditions during and after the COVID-19 pandemic. Originality/value: This study contributes to the literature on virtual communities. Specifically, it considers how social capital influences trust, which subsequently affects information sharing based on the CAB context among Indonesian student’ Facebook users.

Biodegradable film-based packaging is a current concern to replace packaging that depends on petroleum. This is because petroleum-based packaging is very unfriendly to the environment. The bioresource-based biodegradable film has the disadvantage that its mechanical properties are still low, that it requires two or three bioresource materials to be used as polymer hybrids. As a film hybrid polymer that has superior properties such as flexibility, strength, heat resistance, and environmental resistance, it can be applied to various packaging materials and can be developed for various purposes. In this review, the authors review biomass sources as a matrix, as a filler in hybrid polymer-based packaging, the properties of the biodegradable file, and the development for the future. In addition to the raw materials as matrices and fillers, the synthesis method is also described. The properties of biodegradable hybrid polymer film include physicochemical, mechanical, and thermal. This review also summarizes the emerging aspects of bioresources for the development of sustainable and biodegradable hybrid polymer film friendly to the environment.

Nanocrystalline cellulose was extracted from pineapple crown leaf as agricultural waste. Nanocrystalline cellulose was successfully extracted using chemical treatments followed by acid hydrolysis using sulfuric acid. Hydrolysis of pineapple crown leaf was carried out by using different hydrolysis time while maintaining acid concentration and temperature. The properties of nanocrystalline cellulose were obtained such % yield, moisture content, crystallinity index (CrI) and functional group present were studied. The yield shown a comparable result regardless of different reaction time of hydrolysis. While Fourier transform infrared spectroscopy (FT-IR) showed the progressive removal of non-cellulose content and showed the cellulose molecular structure remains unchanged with the reaction time. X-ray diffraction (XRD) analysis revealed that the crystallinity increased linearly with increasing hydrolysis time. The result showed potential of pineapple crown leaf to be used in nanocrystalline cellulose synthesis process and optimum hydrolysis time was determined based on the properties of nanocrystalline cellulose.

Among the main bio-based polymer for food packaging materials, whey protein isolate (WPI) is one of the biopolymers that have excellent film-forming properties and are environmentally friendly. This study was performed to analyse the effect of various concentrations of bio-based nanocrystalline cellulose (NCC) extracted from pineapple crown leaf (PCL) on the properties of whey protein isolate (WPI) films using the solution casting technique. Six WPI films were fabricated with different loadings of NCC from 0 to 10 % w/v. The resulting films were characterised based on their mechanical, physical, chemical, and thermal properties. The results show that NCC loadings increased the thickness of the resulting films. The transparency of the films decreased at higher NCC loadings. The moisture content and moisture absorption of the films decreased with the presence of the NCC, being lower at higher NCC loadings. The water solubility of the films decreased from 92.2% for the pure WPI to 65.5% for the one containing 10 % w/v of NCC. The tensile strength of the films peaked at 7% NCC loading with the value of 5.1 MPa. Conversely, the trend of the elongation at break data was the opposite of the tensile strength. Moreover, the addition of NCC produced a slight effect of NCC in FTIR spectra of the WPI films using principal component analysis. NCC loading enhanced the thermal stability of the WPI films, as shown by an increase in the glass transition temperature at higher NCC loadings. Moreover, the morphology of the films turned rougher and more heterogeneous with small particle aggregates in the presence of the NCC. Overall, the addition of NCC enhanced the water barrier and mechanical properties of the WPI films by incorporating the PCL-based NCC as the filler.