Kenaf (Hibiscus cannabinus L.) Seed and its Potential Food Applications: A Review

A review of recent developments in kenaf fiber/polylactic acid composites research

Kenaf fiber has recently garnered exponential interest as reinforcement in composite materials across diverse industries owing to its superior mechanical attributes, ease of manufacture, and inherent biodegradability. In the discourse of this review, various methods of manufacturing kenaf/Polylactic acid (PLA) composites have been discussed meticulously, as delineated in recently published scientific literatures. This paper delves into the chemical modification of kenaf fiber, examining its consequential impact on tensile strength and thermal stability of the kenaf/PLA composites. Further, this review illuminates the role of innovative 3D printing techniques and fiber orientation in augmenting the mechanical robustness of the kenaf/PLA composites. Simultaneously, recent insightful explorations into the acoustic properties of the kenaf/PLA composites, underscoring their potential as sustainable alternative to conventional materials have been reviewed. Serving as a comprehensive repository of knowledge, this review paper holds immense value for researchers aiming to utilize the capabilities of kenaf fiber reinforced PLA composites.

Cultivation Strategies of Kenaf (Hibiscus cannabinus L.) as a Future Approach in Malaysian Agriculture Industry

In recent years, kenaf has gained significant global attention as a more cost-effective, adaptable, and manageable alternative to other fibre crops. India and China, with nearly 70% of the global kenaf production, have emerged as the leading producers of kenaf plants. While kenaf was traditionally valued for its paper production, it has evolved into a multipurpose crop with diverse industrial applications over the past two decades. Conventional soil-based cultivation methods for kenaf require up to six months for plant maturity. However, in vitro propagation techniques offer a promising alternative that enables faster growth and reduced labour costs. In vitro propagation can be achieved using solid and liquid media, with limited research available on the pure liquid culture method for kenaf. This review aims to introduce and compare the production of kenaf using solid and liquid media, with a specific focus on the emerging country of Malaysia, which seeks to harness the potential of kenaf cultivation for the 15th Sustainable Development Goal, “life on land”, and its contribution to the economy.

Recent Advances in Natural Fibre-Based Materials for Food Packaging Applications

Packaging is one of the major domains in the food processing industry that reduces waste and enhances product shelf life. Recently, research and development have focused on bioplastics and bioresources to combat environmental issues caused by the alarming growth of single-use plastic waste food packaging. The demand for natural fibres has recently increased because of their low cost, biodegradability and eco-friendliness. This article reviewed recent developments in natural fibre-based food packaging materials. The first part discusses the introduction of natural fibres in food packaging, with a focus on fibre source, composition and selection parameters, while the second part investigates the physical and chemical ways to modify natural fibres. Several plant-derived fibre materials have been utilised in food packaging as reinforcements, fillers and packaging matrices. Recent investigations developed and modified natural fibre (physical and chemical treatments) into packaging using casting, melt mixing, hot pressing, compression moulding, injection moulding, etc. These techniques majorly improved the strength of bio-based packaging for commercialisation. This review also identified the main research bottlenecks and future study areas were suggested.

Utilizing Nutritional and Polyphenolic Compounds in Underutilized Plant Seeds for Health Application

Plants represent a significant part of the human diet. Humans have utilized every part of plants for survival, and seeds are no exception. Seeds offer high protein, unsaturated fats, fibre, essential vitamins, and minerals for various food applications. They are also a promising reservoir of bioactive compounds, where various phytochemicals, such as polyphenolic compounds, capable of maintaining and improving well-being, are present in abundant quantities. Plants from Malvaceae and Cannabaceae families are known for their fibre-rich stems that benefit humankind by serving numerous purposes. For many centuries they have been exploited extensively for various commercial and industrial uses. Their seeds, which are often regarded as a by-product of fibre processing, have been scientifically discovered to have an essential role in combating hypercholesterolemia, diabetes, cancer, and oxidative stress. Maximizing the use of these agricultural wastes can be a promising approach to creating a more sustainable world, in accordance with the concept of Sustainable Development Goals (SDGs).

Effect of Kenaf Fibre as Reinforcing Fillers in Corn Starch-Based Biocomposite Film

Biocomposite films were prepared using corn starch (CS), sorbitol as a plasticiser, and multi-scale kenaf fibre as reinforcing filler. The microstructure and the physical, tensile, and water barrier properties of corn starch reinforced with kenaf fibre were characterised and investigated. The biocomposite films were developed via the solution casting technique using 10 g of CS with 0 to 8% kenaf fibre as filler treated with 30% (w/w, starch basis) of sorbitol. The increased amount of kenaf fibre introduced contributed to improvements in film thickness, weight, and density. Conversely, slight reductions in the biocomposite films’ moisture content, water absorption, and solubility rating were 9.86–5.88%, 163.13–114.68%, and 38.98–25.17%, respectively. An X-ray diffraction (XRD) test revealed that the films were amorphous and that there was no effect on the crystallinity structure of films with kenaf fibre reinforcement. Fourier transform infrared (FT-IR) and rheological analysis indicated that kenaf fibre could weaken the molecular interaction of the film matrix. Field emission scanning electron microscope (FESEM) revealed the arrangement and uniform distribution of kenaf fibre at 0.2–0.8%. The incorporation of kenaf increased the tensile strength, Young’s modulus, and elongation at break until (6% wt) of fibre. With the kenaf fibre incorporation, the optimal tensile strength, Young’s modulus, and elongation at break of the films reached 17.74 MPa, 1324.74 MPa, and 48.79%, respectively. Overall, the introduction of kenaf fibre as filler enhanced the physical and mechanical properties of CS films.

Health Hazard Assessment Due to Slimming Medicinal Plant Intake

According to the World Health Organization (WHO), about 80% of people rely on medicinal plants for their primary health needs. Traditional medicine's principal benefits are their vast population knowledge, low severe adverse effects rate, low cost, and the lack of a medical prescription to use them. While obesity has become a global health issue, an increase in finding cheap and fast ways to lose weight escalates medicinal herbs' use for this purpose, both in dietary supplements or in teas. At the same time that Brazil aims to expand traditional medicine, reports regarding toxicology and poisoning put natural products' safety in check. Plants can accumulate heavy metals and metalloids leading to health risks; however, there is a lack of information on that matter, possibly due to a lack of international standardization regarding elemental contamination - this study aimed to determine metal and metalloid concentrations in slimming medicinal plants and their respective teas and evaluate their safety consumption. Metal and metalloid content were determined by inductively coupled plasma optical emission spectrometry (ICP OES). All plants and teas were within the set limits for tolerable upper intake level (UL), provisional tolerable daily maximum intake (PTDMI), and provisional tolerable weekly intake (PTWI). The hazard quotient index (HQ) was above 1 for almost all plants, and the Hibiscus sabdariffa tea regarding aluminum content. The arsenic level was above the Brazilian Pharmacopeia limit in natura plants demonstrating risk in their consumption. Some herbs also presented detection for elements with no safety limits set, such as lead, cadmium, and arsenic, which could mark as a red flag for consumption once their security intake is not precise yet.

Oilseed meals into foods: an approach for the valorization of oilseed by-products

The excellent health benefits of oil extracted from seeds have increased its application in foods, pharmaceutical and cosmetic industries. This trend leads to a growing research area on their by-products, oilseed meals, to minimize environmental and economic issues. Examples of these by-products are soybean, peanut, kenaf seed, hemp, sesame, and chia seed meals. It is well known that soybean meals have wide applications in food and non-food industries, while other seed meals are not well established. Most oilseed meals are rich in health beneficial compounds and are potential sources of plant protein, dietary fiber, and antioxidants. Many studies have reported on the valorization of these by-products into value-added food products such as bakery and meat products to increase their nutritional and functional properties. These efforts contribute to the sustainability, development of novel functional food and support the zero-waste concept for the environment. This review aims to provide information on the composition of selected oilseed meals from soybean, peanut, hemp, kenaf, sesame and chia seeds, their potential applications in the bakery, meat, beverage, pasta, and other food products, and to highlight the issues and challenges associated with the utilization of oilseed meals into various food products.

Culture and community perceptions on diet for maternal and child health: a qualitative study in rural northern Ghana

Background

This study explored cultural and community perceptions of optimal diet for maternal and child health in northern Ghana.

Methods

This was an exploratory cross-sectional study using qualitative methods for data collection. Data were collected between March and April 2019 consisting of 10 focus group discussions with men and women community members between 18 and 50 years in the Kassena-Nankana districts of Ghana. Data were organised using QSR NVivo 12 qualitative software to facilitate thematic analysis.

Results

All study participants recognised the importance of an optimal diet for mother, child and better pregnancy and breastfeeding outcomes. However, there were different cultural beliefs and taboos about what foods are healthy and non-healthy for women at different stages of the reproductive period. Foods perceived to be unhealthy for pregnant women were fatty foods and fresh meat (uncooked or unprocessed meat) due to the belief that they can lead to delivery complications, which many women feared. In addition, some participants relayed the cultural belief that pregnant woman should not eat eggs because it would make the child a thief. Lactating mothers are not to eat foods such as vigna subterranean known locally as bambara bean and “gari” (local meal made from cassava) because it is believed to inhibit breastmilk production. Participants emphasised that food insecurity and economic constraints meant women could not achieve optimal diet and could not afford to be selective in food choices.

Conclusion

Community members recognized the importance of optimal nutrition but were constrained by poverty and cultural barriers. A dual approach which targets improvements of local food production and economic empowerment in combination with community-based discussion and education of the impacts of food taboos on health, should facilitate improvement in the diets of women and future generations.

Dietary Fiber: Fractionation, Characterization and Potential Sources from Defatted Oilseeds

Dietary fiber (DF) has wide applications, especially in the food and pharmaceutical industries due to its health-promoting effects and potential techno-functional properties in developing functional food products. There is a growing interest in studies related to DF; nevertheless, there is less focus on the fractionation and characterization of DF. The characteristics of DF fractions explain their functionality in food products and provide clues to their physiological effects in food and pharmaceutical industrial applications. The review focuses on a brief introduction to DF and methods for its fractionation. It discusses the characterization of DF in terms of structural, physicochemical and rheological properties. The potential sources of DF from selected defatted oilseeds for future studies are highlighted.

A network pharmacology study on main chemical compounds from Hibiscus cannabinus L. leaves

Hibiscus cannabinus L. leaves (HCLLs) are considered a favorable source of natural antiobesity substances. However, actual bioactive compound(s) in it and their mechanism(s) against obesity have not been confirmed. Hence, network pharmacology was conducted to identify its key compounds and mechanism(s) against obesity. Compounds in HCLLs were identified through GC-MS analysis and screened by Lipinski's rule. Genes related to the selected compounds and obesity were obtained from public databases, and overlapping genes between HCLL compound-related genes and obesity target genes were selected using a Venn diagram. The networking between selected compounds and overlapping genes was then constructed, visualized, and analyzed by RStudio. Finally, the binding affinity between compounds and genes was evaluated via molecular docking (MD). A total of 30 compounds in HCLLs were detected via GC-MS, and Lipinski's rule accepted all compounds. The compound-related genes (570 genes) and obesity targeted genes (3028 genes) were identified, and between them, 64 overlapping genes were selected. Gene Set Enrichment Analysis (GSEA) displayed that the mechanisms of HCLLs against obesity were associated with 13 signaling pathways on 22 compounds in HCLLs. Superficially, AKT1, vitamin E, and RAS signaling pathways were noted as a hub gene, an uppermost bioactive compound, and a hub signaling pathway, respectively. However, the binding affinity of ligands and proteins on the RAS signaling pathway was very low; instead, the PPAR signalling pathway was evaluated with potent efficacy against obesity through MD. On the PPAR signaling pathway, α-amyrin was found as the most significant compound for the amelioration of obesity. α-Amyrin manifested the strongest binding affinity on six target proteins associated with the PPAR signaling pathway. Our study suggests that an auxiliary (PPAR) signaling pathway of HCLLs might intervene efficiently against obesity over the hub (RAS) signaling pathway.

Hibiscus cannabinus L. (kenaf) studies: Nutritional composition, phytochemistry, pharmacology, and potential applications

The electronic database was searched up to July 2020, using keywords, kenaf and roselle, chemical constituents of kenaf and roselle, therapeutic uses of kenaf and roselle. Journals, books and conference proceedings were also searched. Investigations of pharmacological activities of kenaf revealed that this edible plant exhibits a broad range of therapeutic potential including antioxidant, antimicrobial, antityrosinase, anticancer, antihyperlipidemia, antiulcer, anti-inflammatory, and hepatoprotective activities. Kenaf also showed versatile utility as a functional ingredient in food, folk medicine, and animal nutritions, as well as in nanotechnology processes. The exploitation of underexploited kenaf by-products can be a significant part of waste management from an economic and environmental point of view. In addition, kenaf showed comparable nutritional, phytochemical, and pharmacological properties with Hibiscus sabdariffa (Roselle). This review has important implications for further investigations and applications of kenaf in food and pharmaceuticals industry.