Avocado Peels and Seeds: Processing Strategies for the Development of Highly Antioxidant Bioplastic Films

Food waste to resource recovery: a way of green advocacy

Due to the massive growth in population and urbanization, there has been a huge increase in the volume of food waste globally. The Food and Agriculture Organization (FAO) has estimated that around one-third of all food produced each year is wasted. Food waste leads to the emission of greenhouse gas and depletion of the soil fertility. Nevertheless, it has immense potential for the recovery of high-value energy, fuel, and other resources. This review summarizes the latest advances in resource recovery from food waste by using technologies that include food waste-mediated microbial fuel cell (MFC) for bioenergy production. In addition to this, utilization of food waste for the production of bioplastic, biogas, bioethanol, and fertilizer has been also discussed in detail. Competitive benefits and accompanying difficulties of these technologies have also been highlighted. Furthermore, future approaches for more efficient use of food waste for the recovery of valuable resources have been also offered from an interdisciplinary perspective.

Sustainable papaya plant waste and green tea residue composite films integrated with starch and gelatin for active food packaging applications

This study explores the sustainable utilization of wastes from a papaya plant (papaya peels (PP), papaya seeds (PS), leaf-stem (PL)) and dried green tea residues (GTR) for the synthesis of bioplastics. The dried GTR were individually blended with each papaya waste extract and then boiled in water to get three composite papaya plant waste-green tea supernatants. Potato starch and gelatin-based functional films were prepared by integrating each with the composite papaya waste-green tea supernatant liquid. This work introduces a dissolved organic matter (DOM) study to the field of bioplastics, with the goal of identifying the organic components and macromolecules inherent in the PW supernatants. When compared with the films prepared solely from papaya waste (PW) supernatants, PW-GTR composite supernatant films prevent UV light transmission with superior antioxidant and mechanical properties. Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction spectroscopy (XRD), and atomic force microscopy (AFM) were utilized to characterize the starch and gelatin PW-GTR films. Owing to the exceptional antioxidant, UV barrier, and remarkable biodegradable properties of the starch/PW/GTR and gelatin/PW/GTR composite films, make them ideal for use in food packaging applications.

Avocado seed starch: Effect of the variety on molecular, physicochemical, and digestibility characteristics

Agro-industrial residues can increase environmental pollution owing to poor knowledge of the use of some components, such as dietary fiber, protein, starch, minerals, and bioactive compounds, which can be used in the food industry. This study compared the molecular, physicochemical, and digestibility characteristics of three avocado seed starches (Criolla, Fuerte, and Hass). Starch was extracted through successive washing and sedimentation. The morphology, size distribution, thermal properties, pasting properties, infrared spectra with Fourier transform, size distribution of amylopectin chains, and digestibility of the three avocado seed strains were analyzed. The starch grains were oval and spherical in shape. The average size of Criolla avocado starch (24.55 μm) was the largest, followed by Hass and Fuerte starches (21.37 μm). Higher gelatinization enthalpy (8.55 J/g), gelatinization temperature (75.28 °C), and pasting temperature (75.57 °C) were observed for Fuerte avocado starch, followed by Hass and Criolla starches. Hass avocado starch exhibited higher maximum (836.27 mPa.s), final (1407.37 mPa.s), setback (588.78 mPa.s), and breakdown (17.68 mPa.s) viscosities than Criolla and Fuerte avocado starches. In addition, the probed avocado starches exhibited high content of resistant starch (60.06-68.90%). Therefore, it was demonstrated that differences in the chemical composition and structure of avocado starch can affect the digestibility of native starch.

A Review on the Potential Bioactive Components in Fruits and Vegetable Wastes as Value-Added Products in the Food Industry

The food production industry is a significant contributor to the generation of millions of tonnes of waste every day. With the increasing public concern about waste production, utilizing the waste generated from popular fruits and vegetables, which are rich in high-added-value compounds, has become a focal point. By efficiently utilizing food waste, such as waste from the fruit and vegetable industries, we can adopt a sustainable consumption and production pattern that aligns with the Sustainable Development Goals (SDGs). This paper provides an overview of the high-added-value compounds derived from fruit and vegetable waste and their sources. The inclusion of bioactive compounds with antioxidant, antimicrobial, and antibrowning properties can enhance the quality of materials due to the high phenolic content present in them. Waste materials such as peels, seeds, kernels, and pomace are also actively employed as adsorbents, natural colorants, indicators, and enzymes in the food industry. Therefore, this article compiles all consumer-applicable uses of fruit and vegetable waste into a single document.

From trash to treasure: review on upcycling of fruit and vegetable wastes into starch based bioplastics

Growing public concern toward environmental sustainability is currently motivating a paradigm shift toward designing easily degradable plastics that can replace conventional synthetic plastics. The massive rise in food waste generation has led to an increased burden on landfills, thereby resulting in the higher emission of greenhouse gases. Using this food waste to produce bioplastics will benefit not only the environment but also develop a systematic food waste management system. Moreover, bioplastics are preferred due to the use of biomaterials derived from renewable resources. Furthermore, bioplastics degrade faster than conventional synthetic plastics, which take years to degrade. The biodegradation of bioplastics occurs under normal environmental conditions and disintegrates into carbon dioxide, water, biomass, and inorganic compounds without producing hazardous residues. In this review, we will discuss the synthesis of starch based bioplastics using discarded parts of various fruits and vegetables. Furthermore, we will address the importance of various components in the development of starch based bioplastics, such as fillers, plasticizers, and other additives that are essential in providing the bioplastic with different physio-mechanical properties. Therefore, bioplastic production using food waste will pave the way to achieve systematic waste management and environmental sustainability in the near future.

Quality Parameters of PE-Pomace Based Membranes

This paper presents the results of research on selected mechanical and physical properties of polyethylene membranes containing 50% of the plant fraction obtained as waste from an edible oil press. The produced biomembranes were characterized by low tensile strength (2.02-4.28 MPa). The addition of plant material will not adversely affect the barrier properties such as water vapor permeability or the contact angle. Additionally, there was a discoloration of the characteristics affecting the shrinkage of the membrane. The presence of the plant component clearly lowered the shrinkage of the material. This research is important and provides valuable knowledge on the possibilities of using plant waste and the direction of the potential application of the materials produced with their use.

Biodegradable and Biobased Mulch Films: Highly Stretchable PLA Composites with Different Industrial Vegetable Waste

Highly stretchable biobased and biodegradable agricultural mulch films based on polylactic acid (PLA) and 10, 20, or 30 wt % various nonedible vegetable wastes such as spinach stems (SS), tomato pomace (TP), and cocoa shells (CS) are prepared and characterized in this work. The results demonstrate that appropriate PLA plasticization and vegetable waste addition allow for obtaining films suitable for mulching with tensile strengths in the 10-24 MPa range and elongations at break up to 460%, depending on the kind and amount of vegetable waste incorporated. Additionally, the developed mulches show low water solubility (1-15 wt %) and moisture content (1-3 wt %) with a water vapor permeability of up to 3 × 10^-10 g s^-1 m^-1 Pa^-1, similar to that of Mater-Bi. In addition, the type of vegetable waste added as filler were demonstrated to significantly affect not only the films' mentioned properties but also their biodegradability. For instance, films prepared with 20 wt % SS were demonstrated to improve PLA soil biodegradability, which increased from 0 to 38 wt % for PLA composites after 6 months of a soil burial experiment. Lastly, the developed composites contain different amounts of plant micro- and macronutrients, indicating their potential as fertilizers. The results found in this work represent a sustainable, fully biobased alternative to other mulches already in the market.

Food and cosmetic applications of the avocado seed: a review

Avocado seed waste has increased as avocado products have become commercialized since the seed is considered inedible. However, by exploring the potential uses of the seed, the unrecyclable waste produced by the avocado industry can be reduced. This paper aims to review and discuss current literature on the food and cosmetic applications of avocado seeds and their constituents. In descending order, avocado seeds contain starch, water, lipids, protein, phytochemicals, antinutrients, vitamins, and minerals. As for food applications, starch can be used as a bioplastic, flour, thickening agent, and emulsifier. Additionally, extracts containing avocado seed phytochemicals show antimicrobial and preservative activities, which can find use in meat products and in producing an orange dye. When considering cosmetic applications, patented avocado seed extract formulations have proven useful in skincare. Also, the avocado seed lipids, in the form of fatty acids, can be processed into soap. By applying the ideas presented in this review, the toll avocado seeds take on the environment would be reduced, improving the sustainability of the avocado market. As a result, avocado seeds can contribute to the emerging bioeconomy market for food and cosmetic applications.