استكشف المجموعة الواسعة من العناوين المتاحة.

Industrial by-products are produced every day through fruit processing industries. Pineapple is not an exception; when processed, around 60% (w/w) of its weight are peels, stem, trimmings, and crown, the only used fruit part for human consumption. Due to high concerns of sustainability in the food system and negative high impact of human practice in the environment, a strategy has to be developed. Therefore, a green chemistry approach was applied to pineapple by-products to make an integrated valorization by the extraction of bioactive molecules. Two pineapple by-products (peels and stems) were studied, applying a green chemistry approach, which means the non-use of organic solvents or extreme methodologies. A subdivision of each by-product was done by the application of a juice machine. The peels and stems in the fresh state were ground separately, creating two fractions for each by-product—a juice and a wet pulp (press cake). The press cake was characterized, dried, and ground to create a fine powder flour. To the juice, a precipitation methodology with polysaccharides was applied, which allowed the bromelain separation (developing of an enzymatic fraction) from the fruit juice. The enzymatic extract was freeze-dried, and the juice was spray-dried, developing two more fine powders. Thus, three new ingredients were produced from each by-product, creating a total of six new ingredients. Overall, the enzymatic fractions represented around 0.26% (w/w) of pineapple weight. Pineapple stem juice represented 4.8% (w/w), and peel juice represented 17.3% (w/w). Pineapple stem flour represented 3.1% (w/w), and peel flour represented 11.4% (w/w) of the total pineapple weight. To valorize the by-products juices, a full characterization was performed of bioactive molecules and biological activities. When comparing the two juices, the peel juice showed lower content of total phenolic compounds, lower antioxidant capacity, and lower content of vitamin C. The different phenolic compounds were identified by HPLC analysis in the two pineapple by-products juices. However, the same compounds in both juices were quantified (chlorogenic, caffeic, and ferulic acids). On the other hand, the by-products flours had a high content of insoluble dietary fiber (IDF), mainly cellulose and hemicellulose. Therefore, the approach applied in this work opens the door to the production of green products, as a result of by-products valorization. This could be applied not only in the food industry but also in the nutraceutical and cosmetic industries.

There's a conflict over \"ham\" as they prepare the outlandish stir-fry: pineapple fried rice.

Composite materials are gaining popularity due to their better mechanical qualities and low weight. This study focuses on enhancing forces of flexural and tensile characteristics in epoxy-based composites by incorporating reinforced carbon fibers extracted from pineapple leaves in combination with cobalt filler. The reinforcement of natural fibers in composite materials addresses environmental concerns and contributes to improved mechanical attributes. Hand lay-ups of pineapple leaf fiber (PALF) and epoxy compound by carbon fiber were created proportion of weight (wt%) by adjusting cobalt 0.25 to 1.0 wt%. The flexural strength of PALF is around 101 MPa, and the Tensile strength of PALF is around 92.94 MPa. Whereas the Flexural strength of CF is around 343.54 MPa, and the Tensile strength of CF is around 181.32 MPa. Compared to pure epoxy, 51.25% increased strength and considerable improvement of flexural and tensile specimens. 0.5 wt% inclusion of nano Cobalt filler component confirms favorable strength test findings in PALF/CF epoxy combination.

Background WRKY proteins comprise a large family of transcription factors that play important roles in many aspects of physiological processes and adaption to environment. However, little information was available about the WRKY genes in pineapple ( Ananas comosus ), an important tropical fruits. The recent release of the whole-genome sequence of pineapple allowed us to perform a genome-wide investigation into the organization and expression profiling of pineapple WRKY genes. Results In the present study, 54 pineapple WRKY (AcWRKY) genes were identified and renamed on the basis of their respective chromosome distribution. According to their structural and phylogenetic features, the 54 AcWRKYs were further classified into three main groups with several subgroups. The segmental duplication events played a major role in the expansion of pineapple WRKY gene family. Synteny analysis and phylogenetic comparison of group III WRKY genes provided deep insight into the evolutionary characteristics of pineapple WRKY genes. Expression profiles derived from transcriptome data and real-time quantitative PCR analysis exhibited distinct expression patterns of AcWRKY genes in various tissues and in response to different abiotic stress and hormonal treatments. Conclusions Fifty four WRKY genes were identified in pineapple and the structure of their encoded proteins, their evolutionary characteristics and expression patterns were examined in this study. This systematic analysis provided a foundation for further functional characterization of WRKY genes with an aim of pineapple crop improvement.

Developing green and facile synthesis techniques for biomaterials has been widely advocated recently. In this study, we report a green and facile approach to prepare pineapple peel cellulose/magnetic diatomite hydrogels in an environmentally benign ionic liquid, 1-butyl-3-methylimidazolium chloride. The structure, swelling and methylene blue (MB) adsorption of the prepared hydrogels were investigated. The results of FTIR, XRD and SEM confirmed the successful embedment and dispersion of m-DE in hydrogel networks. The TG results indicated the improvement of thermal stability due to the presence of m-DE. The VSM results showed the superparamagnetic nature of the prepared hydrogels endowed by m-DE. Moreover, an appropriate addition of m-DE could enhance the swelling ability and MB adsorption capacity of the hydrogels. The MB adsorption process was fast (reaching equilibrium in 30 min) and fitted well with pseudo-second-order kinetic model and Langmuir isotherm model. The maximum adsorption capacity calculated from Langmuir isotherm model was 101.94 mg/g, obviously higher than the hydrogel prepared without m-DE addition (75.87 mg/g). Furthermore, the prepared hydrogels exhibited a good stability and reusability for MB adsorption. This work presents an alternative for the green construction and enhanced performance of cellulose-based hydrogels. Graphical abstract

Hydrolysis and fermentation processes are key stages in xylitol production from lignocellulosic materials. In this study, pineapple cores, one of the wastes from the canned pineapple industry, were used as raw material for xylitol production. Two methods was used for hydrolysis: enzymatically using commercial enzyme Cellic HTec2, and acid hydrolysis using 4% H[sub.2] SO[sub.4] . In contrast, the fermentation process was carried out with two selected yeasts commonly employed in xylitol fermentation, Debaryomycess hansenii, and Candida tropicalis. Before these two processes, the pineapple cores were characterized using the Van Soest method to determine their lignocellulosic content. The hemicellulose content was 36.06%, the cellulose content was 14.20%, and the lignin content was 10.05%. This result indicates that the hemicellulose content of pineapple cores has the potential to be used as a raw material in the production of xylitol. The hydrolysis efficiency of enzymatic hydrolysis was 21% higher than that of acid hydrolysis. The highest xylitol and biomass yield of 0.371 g[sub.xylitol] /g[sub.xylose] and 0.225 g[sub.cell] /g[sub.xylose] were observed by C. tropicalis using an enzymatic hydrolysate.

Natural fibers are gaining too much attention and researchers are shifting their interest due to environmental concern and ecological benefits. The present experimental study is focused on the investigation of thermo-mechanical properties of aggro–waste pineapple leaf fiber (PALF) reinforced polymer composite under the influence of pineapple micro-particulate inclusion. For developing the hybrid composites, constant weight fraction (30%) of PALF and five different weight fractions (2.5%, 5%, 7.5% and 10%) of particulates are taken. The study involves preparation, chemical treatment (with 5% NaOH solution) and characterization (XRD, FTIR and TGA) of micro particulate and results revealed that the treatment of particulate has a better crystalline index and thermal stability which improved their material characterization as well as mechanical and thermal properties. The addition of chemically treated particulates in PALF reinforced polymer composites showed better interfacial bonding between fibers and matrix that enhanced the mechanical and thermal properties of the developed composite. The experimental results showed that 7.5% of particulates inclusion has highest tensile, flexural, compressive and hardness properties with higher plane strain fracture toughness and thermogravimetric analysis while 2.5% of particulate inclusion has highest impact strength. The water absorption and biodegradability tests were also performed and revealed that the addition of particulates has greater water absorption and better biodegradability. The scanning electron microscopy was used to study the morphology behaviour with different weight fraction of particulates and also analyzed the fracture behaviour of developed hybrid composites.

Alginate-based edible films containing natural antioxidants from pineapple peel were applied in the microbial spoilage control, color preservation, and barrier to lipid oxidation of beef steaks under storage at 4 °C for five days. Different stabilization methods of pineapple peel compounds were used before incorporation into alginate films, including extracted compounds with an hydroalcoholic solvent encapsulated in microparticles, microparticles produced by spray-drying pineapple peel juice, and particles obtained by milling freeze dried pineapple peel. Bioactive films exhibited higher antioxidant activity (between 0.15 µmol to 0.35 µmol FeSO4.7H2O/g dried film) than the alginate film without these compounds (0.02 µmol FeSO4.7H2O/g dried film). Results showed that control films without active compounds had no significant effect on decreasing the microbial load of aerobic mesophilic and Pseudomonas spp., while the films containing encapsulated hydroalcoholic extract showed a significant inhibitory effect on microbial growth of meat at two days of storage. Alginate films containing peel encapsulated extract were effective for maintaining the color hue and intensity of red beef meat samples. Pineapple peel antioxidants have the potential to retard lipid oxidation in meat samples, and the possibility of incorporation of a higher amount of pineapple peel bioactive compounds in the films should be investigated.

A pineapple peel hydroalcoholic extract rich in phenolic compounds, was stabilized by microencapsulation using spray drying technology, with maltodextrin, inulin, and arabic gum as wall materials. The influence of the type of wall material and drying temperature (150 and 190 °C) on the particles properties was studied. The particles presented a spherical shape with a diameter ranging from approximately 1.3 to 18.2 µm, the exception being the ones with inulin that showed a large degree of agglomeration. All powders produced presented an intermediate cohesiveness and a fair to good flowability according to Carr index and Hausner ratio, which envisages suitable handling properties at an industrial scale. The microencapsulation processes using maltodextrin and arabic gum at 150 °C were the ones that showed higher maintenance of the antioxidant activity of compounds present in the extract before encapsulation during spray drying. In addition, the microparticles obtained were quite efficient in stabilizing the encapsulated phenolic compounds, as their antioxidant activity did not change significantly during six months of storage at 5 °C.

The application of natural fibers is increasing rapidly in the polymer-based composites. This study investigates manufacturing and characterization of polypropylene (PP) based composites reinforced with three different natural fibers: jute, kenaf, and pineapple leaf fiber (PALF). In each case, the fiber weight percentages were varied by 30 wt.%, 35 wt.%, and 40 wt.%. Mechanical properties such as tensile, flexural, and impact strengths were determined by following the relevant standards. Fourier transform infrared (FTIR) spectroscopy was employed to identify the chemical interactions between the fiber and the PP matrix material. Tensile strength and Izod impact strength of the composites significantly increased for all the composites with different fiber contents when compared to the pure PP matrix. The tensile moduli of the composites were compared to the values obtained from two theoretical models based on the modified “rule of mixtures” method. Results from the modelling agreed well with the experimental results. Tensile strength (ranging from 43 to 58 MPa), flexural strength (ranging from 53 to 67 MPa), and impact strength (ranging from 25 to 46 kJ/m2) of the composites significantly increased for all the composites with different fiber contents when compared to the pure PP matrix having tensile strength of 36 MPa, flexural strength of 53 Mpa, and impact strength of 22 kJ/m2. Furthermore, an improvement in flexural strength but not highly significant was found for majority of the composites. Overall, PALF-PP displayed better mechanical properties among the composites due to the high tensile strength of PALF. In most of the cases, T98 (degradation temperature at 98% weight loss) of the composite samples was higher (532–544 °C) than that of 100% PP (500 °C) matrix. Fractured surfaces of the composites were observed in a scanning electron microscope (SEM) and analyses were made in terms of fiber matrix interaction. This comparison will help the researcher to select any of the natural fiber for fiber-based reinforced composites according to the requirement of the final product.