Unlocking the potential of value chains as climate change resilience strategies: can macadamia nuts (macadamia integrifolia) offer the gateway?

The consequences of climate change threaten existing agriculture systems across Zimbabwe. The researchers examined the possibility and potential for developing a smallholder farmer driven macadamia nuts value chain. Using the case of Chipinge district, Manicaland province, Zimbabwe, the study evaluated the potential of macadamia nut value chain functions as a climate change resilience strategy in Zimbabwe. Challenges faced by actors and positive developments made in incorporating smallholders into the macadamia nuts production sector were explored. The role of local markets and producers in the international trade in macadamia nuts were also examined, using a modified stakeholder analysis framework. Triangulation, a mixed methodology, was used to adequately capture the various quantitative and qualitative dimensions along the macadamia nuts value chain pillars. A sample of 220 farming units including Estates, A1 and A2 farmers was proportionately selected for the study. Primary data were collected from Key Informants through interviews and personal communications. Secondary data were collected from Agritex officers, buyers, and the Macadamia Association of Zimbabwe farmers’ records. The production-marketing interface for macadamia nuts is weakly coordinated in the study area as shown by the rudimentary production systems especially for the A1 and A2 farmers. Results show that the major missing links are the limited application of extension driven production enhancers and the limited visibility of farmers in more rewarding export markets. Production scales have, however, been increasing with more farmers allocating land towards the macadamia nuts trees. Decentralization of macadamia nuts markets and localized value addition needs to be done to realign domestic and export market prices.

Extracts of Different Organs of Macadamia Nut Tree (Macadamia Integrifolia) Ameliorate Oxidative Damage in D-Galactose Accelerated Aging Model in Rats

Macadamia nut tree, Macadamia integrifolia (Maiden & Betche), is cultivated for the production of the edible macadamia nuts, which are a good source of monounsaturated fatty acids. We investigated the effect of ethanolic extracts of leaves, nuts, and nutshells of macadamia in D-galactose accelerated aging model in rats. Administration of D-galactose (150 mg/kg) in rats for 60 days resulted in impairment of cognitive function and motor coordination and caused an increase in oxidative stress and deterioration of liver and kidney functions. Macadamia nut extract ameliorated cognitive impairment induced by D-galactose as inferred from Morris water maze test and balance test using rotarod. Also, nut extract was superior to leaves and shell extract in reducing serum levels of malondialdehyde (50%), alanine transaminase (63%), aspartate transaminase (63%), total bilirubin (24%), creatinine (38%), and urea (16%) compared to animals that received no treatment. Chemical analysis showed that macadamia nut extract has a high percentage of oleic acid (81%) followed by palmitoleic acid (6.9%). This study encourages further investigation of the health benefits of macadamia nuts and the underlying mechanism of these effects.

Shoot initiation for Macadamia integrifolia explant with tissue culture technique

Macadamia nuts are grown in subtropical and tropical regions and endemic species in Greenland that can be commercially developed in Indonesia. Macadamia’s generative propagation tends to have problems in its seed stock. It often experiences obstacles in field seed stock, and the production requires a long time because it has a thick shell (pericarp). Macadamia initiation needs technology to prevent extinction. One of the propagation is through the technique culture in vitro. This research was conducted to determine the initial response of basic media and to know the response of Macadamia growth in vitro. This research used five media which are Media 1 (DKW with BAP 0.1 ppm, kinetin 0.1ppm), Media 2 (WPM with BAP 1 ppm), media 3 (DKW), media 4 (MS), media 5 (MS with BAP 0.5 ppm). The results showed that media 1 and 3 (DKW media) had a good response for leaf and shoot growth in macadamia explants.

Assessment of the Safe Consumption of Nuts in Terms of the Content of Toxic Elements with Chemometric Analysis

Nuts are characterized by high nutritional value and are recommended as a part of a healthy diet. At the same time, toxic elements could also be found in them. In this research, we measured the content of As, Cd, Pb and Hg in a wide variety of edible nuts. To determine the As content, inductively coupled plasma mass spectrometry (ICP-MS) was applied. Cd and Pb were detected by the electrothermal atomic absorption spectrometry analytical technique (ETAAS) with Zeeman background correction, while atomic absorption spectrometry method (AAS) with the amalgamation technique in the case of Hg was used. The study material consisted of 120 samples without replications (10 for each subgroup) including the following nuts: almonds, Brazil nuts, cashew nuts, hazelnuts, macadamia nuts, peanuts, pecan nuts, pine nuts, pistachios and walnuts. Indicators such as the target hazard quotient (THQ), cancer risk (CR) and hazard index (HI) were used to assess the health risk. The highest median As, Cd, Pb and Hg contents were observed for pistachios (192.42 µg/kg), pine nuts (238.40 µg/kg), peanuts (82.06 µg/kg) and pecans (82.06 µg/kg), respectively. The exceedance of the established limits was found in the case of Pb for nine samples: macadamia nuts (221.49 µg/kg; 2350.94 µg/kg; 2581.43 µg/kg), pine nuts (266.33 µg/kg), peanuts (1353.80 µg/kg) and pecans (2689.13 µg/kg, 2758.26 µg/kg, 2992.29 µg/kg and 3169.41 µg/kg). Extremely high (>2500 µg/kg) Pb content was found in 33% of studied pecans imported from the USA. The health risk indicators did not identify increased health risk. This research is significant considering the food safety issues and indicates the need to regularly control the content of toxic elements in food, as well as to establish the specific limits for heavy metals content in nuts. The chemometric analysis included cluster analysis and principal component analysis (PCA). Cluster analysis made it possible to distinguish four subgroups on the basis of the ability to accumulate toxic elements: pine nuts, pecans, pistachios and other analysed nuts. PCA indicated primarily factor 1, distinguishing mainly pecans, macadamia nuts and peanuts. Chemometric analysis can be a useful tool in estimating the ability of different nut species to accumulate contaminants.

Heat Inactivation of Listeria monocytogenes on Pecans, Macadamia Nuts, and Sunflower Seeds

Listeria monocytogenes is a major concern for the food industry in ready-to-eat (RTE) foods. In recent years, large-scale recalls have occurred with contaminated sunflower seeds and macadamia nuts that triggered product withdrawals.

Demand analysis of peanuts and tree nuts in the United States: a micro-perspective

This paper examines household purchases of peanuts and tree nuts in the United States using the Nielsen Homescan Panel for calendar year 2015. Households located in different regions and from different races and ethnicities along with seasonality were important factors affecting the propensities to purchase and actual quantities purchased. The demand for pecans, almonds, and walnuts was sensitive to price changes. The reverse was true regarding the demands for cashews, macadamia nuts, pistachios, mixed nuts, and peanuts. All nuts were identified as necessities. Findings of this research provide insights for stakeholders in the nut industry, in terms of target marketing, product positioning, and pricing strategies. Moreover, we contribute to the literature by providing a micro-perspective investigation concerning the demand for nut products in the United States. In addition, we provide a more up-to-date analysis concerning factors affecting not only the likelihood of purchasing nuts but also the quantities purchased.

Review of Macadamia Production in Malawi: Focusing on What, Where, How Much Is Produced and Major Constraints

Macadamia is an essential commodity crop in Malawi. The nuts are a lucrative commodity and are used for household consumption, income generation among farming families and as a foreign exchange earning crop at country-level. Macadamia production in Malawi has increased significantly in recent years. Malawi is the seventh top producer of macadamia nuts valued at £23.5 million, with a global market share of 3%. In 2018, the country was the fourth-largest exporter of macadamia nuts that were valued at £18.2 million. The majority (90%) of this crop was grown by large commercial estates with smallholder’s production only contributing about 10% of the total crop production. However, the smallholder sector is vital for the future growth of the macadamia sector in the country. Further, Malawian smallholders consider macadamia production as a low-input crop with large returns per unit area (£10.7 kg−1 ha−1), and it thus a lucrative commodity with high potential for poverty reduction and wealth creation among these farming families. This paper, therefore, explores: (i) the historical and current trends in macadamia nut production in Malawi; (ii) analyses the country’s macadamia value chain focusing on smallholder farmer contributions; and (iii) discusses the constraints of smallholder macadamia production in Malawi for informed policymaking. We conclude that the synthesis of the Malawian macadamia sub-sector provides an understanding of the vital contributions of macadamia to Malawi’s economic growth and improvement of livelihoods.