Experimental assessment on preparation of biodegradable polythylene/polylatic acid-chithosan composite from renewable resources

Due to poor degradability and contamination risk of synthetic plastics, utilization of renewable resources is encouraged. Biobased thermoplastic polymers from renewable resource that is inexpensive, biodegradable, compostable and renewably non-toxic, is focused. In this paper mixtures of synthetic and natural polymers were used as a potential option to reduce pollution by plastic waste. The study is aimed at assessing utilization of sweet potato waste as a source of bioplastic for package application, the polymer was modified with a biopolymer chitosan to obtain polylactic acid-chitosan plastic. The developed polymer matrix was blended with polyethylene to obtain biodegradable packaging material. The bioplastic was characterized using Fourier Transformed Infra-Red Spectroscopy (FTIR) and scaning electron microscope (SEM). Physical and mechanical properties of the composites were evaluated by measuring enzymatic degradation, tensile strength, and elongation at break. The results have shown that the film obtained have homogeneous surface by (SEM). Mechanical properties of the bio plastics revealed that tensile strength increases with increases in the concentration of chitosan and hence, the elongation at break decreases with increase in chitosan content. While the fastest enzymatic degradation was observed to have high microbial growth on the bio plastics with high content of Chitosan-Polylactic acid.

Utilization Of Organic Fertilizer Compost Made From Purple Sweet Potato Waste (Ipomoea Batatas L.) To Increase The Production Of Pakchoy (Brassica Chinensis L.)

Compost is an organic fertilizer made from recycled organic materials. Fertilizers can be made from organic waste or unused organic waste. Purple sweet potato waste can be reused into compost. The purpose of this study was to examine the effectiveness of purple sweet potato waste compost inoculated with Trichoderma harzianum in increasing the production of pakchoi and to determine the treatment of purple sweet potato waste compost to increase the production of pakchoi. The research method used is the experimental method. The experimental design used was RAK (Randomized Block Design) with 1 factor. The experiment consisted of 4 treatments of purple sweet potato compost 25 (B) g, 50 g (C), 75 g (D), 150 g (E), and 1 control (A), and was repeated 5 times. The data analysis technique used analysis of variance (ANOVA). Parameters observed were the number of leaves, plant height, leaf width, plant wet weight, plant dry weight, and root length. The results showed that the application of purple sweet potato compost affected increasing the growth and production of pakchoi. The right treatment in increasing the growth of pakchoi is treatment 150 g or treatment E. Treatment 150 g (E) can increase the number of leaves (13.13), plant height (16.32 cm), leaf width (4.88 cm), wet weight (16.60 g), dry weight (6.35 g), and root length (15.80 cm).

USING RAW POTATO PEEL IN THE PRODUCTION OF EXTRUDED FEED ADDITIVE

The paper is concerned with some aspects of processing raw potato peelings. It presents the dynamics of potato production in the world and in Ukraine, and analyses the figures on yields of this crop. Methods of processing potatoes at Ukrainian enterprises have been considered. It has been found that the bulk of the waste (15–60%) is formed during peeling raw potatoes. Methods of utilisation of potato peelings have been analysed. Problems of using fresh potato peel in the diet of farm livestock have been analysed. The technological operations of potato waste processing have been considered, and it has been substantiated how practical the method of extrusion is. The advantages of manufacturing an extruded feed additive with the use of potato peel have been shown. The physical properties, chemical composition, and term of storage of fresh potato peel have been determined. It has been found that fresh potato peel is poorly storable and hardly flowable, so it must be processed within 48 hours. To produce an extruded feed additive including crushed wheat grain and fresh potato peel in the ratio 9:1, a step-by-step scheme has been developed. The physical properties, the content of individual nutrients and minerals, and the shelf life of the extruded additive have been determined. It has been established that manufacturing the feed additive by the method suggested allows increasing the product’s nutritional value, prolonging its shelf life, improving its sanitary quality, technological properties, and conditions of feeding potato peel to livestock. It has been found that when the amount of potato peel introduced is 10% and that of crushed wheat grain is 90%, the optimal moisture content is 16.5%. Besides, this ratio results in the minimum energy consumption and in a coefficient of expansion high enough. During extrusion, the physical properties change: the moisture content, angle of repose, and bulk density decrease, while the flowability increases, which makes the feed additive suitable for use in the feed products technology. Besides, extrusion of the feed additive is accompanied by reduction in crude protein, crude fibre, and crude fat. It has been established that the shelf life of the additive is 4 months

Bioconversion of potato solid waste into antifungals and biopigments using Streptomyces spp.

Potato waste was processed and used as a sole substrate for simultaneously producing antifungals and biopigments using Streptomyces spp. Out of three different Streptomyces isolates, strain SO6 stood out due to its ability to produce antifungals against economically important fungal phytopathogens and intracellular biopigments using potato waste powders without additional nutrients. This strain also showed the potential to secrete a broad range of enzymes for fermentation of eight sugars that could be involved in potato waste bioconversion. The results of the fermentation assay indicated that Streptomyces sp. strain SO6 degrades potato wastes during submerged fermentation, diminishing total dry weight and increasing reducing sugars from 0.3 to 3.6 mg·mL−1 and total proteins from 70.6 to 187.7 μg·mL−1. The results showed that Streptomyces strain SO6 was able to convert the potato waste into 0.96 mg·g−1 of diffusible antifungals and 1.75 mg·g−1 of reddish-purple biopigments. On the contrary, an absence of pigment production was observed during the fermentation of the commercial medium used as reference. According to our results, replacement of commercial culture media with available low-cost agroindustrial wastes for producing bioactive chemicals is a real opportunity to enhance the Streptomyces pigment production and antibiotic sustainability with cost-competitiveness. To our knowledge, this is the first report on the simultaneous production of biopigments and diffusible antifungal antibiotics produced by Streptomyces spp. using potato solid waste as the sole nutrient source.

Effect of different levels of Ipomoea batatas flour inclusion on the ruminal pH of sheep in metabolic cages

The accumulation of industrial by-products increases the use of sweet potato waste for ruminants, but ruminal pH characteristics are still not well known. The objective was to assess the fluctuation of ruminal pH in sheep supplemented with different levels of sweet potato flour inclusion in their diet. Four rumen-fistulated sheep were used; they were fed a diet based on ryegrass haylage (Lolium multiflorum) and sweet potato flour (Ipomoea batatas), provided according to the level of inclusion in the total diet (0, 0.5, 1.0 and 1.5%). Approximately 80 ml of ruminal fluid was collected for reading on a bench pH meter. Statistical data analysis was run on Statistical Analysis System (SAS Institute INC. Cary, NC, USA), and statistical difference was considered for p < 0.05. The animals that received 1.5% of sweet potato flour in their diet presented acid rumen pH; the 1.0% group presented rumen pH acidification in the first 6 hours after feeding, and the 0.5% level of inclusion did not change the rumen environment. It is concluded that the inclusion of 0.5% sweet potato flour in sheep diet proved to be an efficient energy supplementation strategy.

Integrated Efforts for the Valorization of Sweet Potato By-Products within a Circular Economy Concept: Biocomposites for Packaging Applications Close the Loop

With the aim to fully exploit the by-products obtained after the industrial extraction of starch from sweet potatoes, a cascading approach was developed to extract high-value molecules, such as proteins and pectins, and to valorize the solid fraction, rich in starch and fibrous components. This fraction was used to prepare new biocomposites designed for food packaging applications. The sweet potato residue was added to poly(3-hydroxybutyrate-co-3-hydroxyvalerate) in various amounts up to 40 wt % by melt mixing, without any previous treatment. The composites are semicrystalline materials, characterized by thermal stability up to 260 °C. For the composites containing up to 10 wt % of residue, the tensile strength remains over 30 MPa and the strain stays over 3.2%. A homogeneous dispersion of the sweet potato waste into the bio-polymeric matrix was achieved but, despite the presence of hydrogen bond interactions between the components, a poor interfacial adhesion was detected. Considering the significant percentage of sweet potato waste used, the biocomposites obtained show a low economic and environmental impact, resulting in an interesting bio-alternative to the materials commonly used in the packaging industry. Thus, according to the principles of a circular economy, the preparation of the biocomposites closes the loop of the complete valorization of sweet potato products and by-products.

Effect of Temperature Treatments on the Viability of Clavibacter sepedonicus in Infected Potato Tissue

The objective of the present study was to establish whether exposure to temperatures of 55-70 °C results in eradication of the pathogen Clavibacter sepedonicus (Cs) in colonised potato tissue, in order to evaluate the efficiency of composting for disinfection of Cs-infected potato waste. Pre-sprouted potato tubers were inoculated and planted to produce Cs-colonised stem and tuber material. After incubation in temperature-controlled water baths, the infected potato tissue was analysed for the presence of culturable and pathogenic Cs. Additional experiments were performed with Cs-colonised potato stem tissue crushed and deaerated, thus simulating macerated stem tissue in the compost heap. To enable a comparison with bacterial cells that are not enclosed by their natural organic matrix, temperature treatments were applied to non-infected stem tissue crushed and deaerated, and spiked with freshly prepared Cs-suspensions. Cs settled inside colonised potato tissue, as well as Cs present as Cs-suspensions supplemented to potato tissue, was eradicated by exposure to heat, even after a treatment of 1 h at 55 °C, with the exception of one case in which the pathogen present in intact stem material escaped a treatment of 6 h at 60 °C, indicating that incidentally stems may provide niches in which the pathogen is protected against heat.