Synthesis of malate, however, may unduly tax a carbohydrate-limited root apex. Indeed, Ca2 treatment, which accumulated more NO3 – than the other treatments , contained negligible amounts of malate . In conclusion, NH4 + and NO3 – differentially affect the finescale spatial patterns of uptake, export, assimilation, and carbohydrate content along root apices. Moreover, although NO3 – levels are maintained low in the meristem and the apical part of the growth zone, NO3 – clearly needs to be considered as a significant component of the osmotic pool supporting expansion at the base of the growth zone and sustaining the functions of young, mature root tissues.Unlike most commonly occurring coconuts, the edible solid endosperm often called the ‘meat’ or ‘kernel’ is thicker, with a soft jelly-like texture at maturation. This can be attributed to some unusual physiological and bio-chemicaltraits. Makapuno contains high levels of cytokinins which promotes cell proliferation and expansion that results in greater endosperm thickness compared with normal coconuts . The unlimited growth of the solid endosperm makes Makapuno a model system for tumorigenesis studies in higher plants . Makapuno also lacks – galactosidase activity which leads to the accumulation of higher levels of the water-soluble galactomannan rather than the water insoluble mannan found in normal coconuts . This likely alters cell wall structure and adhesion and produces a highly viscous endosperm . Finally, Makapuno has a higher content of moisture and protein in the endosperm but lower crude fat; the latter trait should reduce rancidity which is important to those food processing industries that use coconut in their products .
These features of the Makapuno coconut are similar to ‘Kopyor’ in Indonesia, ‘Dikiri Pol’ in Sri Lanka, ‘Thairu thengai’ in India , Maphrao Kathi’ in Thailand and Dua Dac Ruot in Vietnam ,vertical planters for vegetables and are all known for their combination of good taste and unique ‘meat’ texture .The unique endosperm of Makapuno may be controlled by a single Mendelian recessive mutation . The described traits are only found in the triploid endosperm and all alleles need to be recessive. Makapuno therefore need to be physically segregated from normal coconut trees to prevent cross pollination. In addition, the highly viscous nature of the inner endosperm makes germination difficult. The need for a triploidhomozygous recessive state and the observed low germination frequency makes Makapuno coconuts a rarity in nature. The result is a sale price that is 3–5 times higher than normal coconuts in South East Asia and that can be 50 times higher than that of normal mature coconuts in Thailand. Although Makapuno is a value-added commodity,to our knowledge, the post harvest behavior of its fruit has not yet been studied. This is important because of the increased demand for fresh coconut fruit in distant markets in Europe and the United States . Previous work showed that normal mature coconut can be stored for 3–5 months post harvest under ambient atmosphere, after which, the liquid endosperm evaporates and the embryo germinates . De-husked mature coconut has a shorter storage life: up to 2 months at 0–1.5 ◦C, or 3 weeks at 12–15 ◦C . Although removal of the husk reduces shelf-life, the cost-benefit analysis is better. These fruit weigh less which lowers long-distance shipping costs and the price can be marked-up as the product is more convenient for the consumer. As described, Makapuno fruit has distinct properties compared to normal coconuts and this would be expected to influence the storage performance and conditions used to maintain its quality.
The overall goal of this study therefore, was to provide basic information on the storage conditions needed to prolong Makapuno coconut storage-life.Fully mature Makapuno coconuts were partially de-husked, leaving a layer of fiber 1–2 cm thick and were transported from Kanchanaburi province to the laboratory at Kasetsart University within 2 days of harvest. Six uniform and damage-free coconuts were packed in strong well ventilated fiberboard cartons with dividers to separate individual fruit and were then stored at 30 ± 2 ◦C, 66 ± 5% relative humidity . Individual fruit was examined for respiration rate, ethylene production rate, weight loss, color, total soluble solid contents , titratable acidity and lipid oxidation of coconut meat expressed as malondialdehyde values and decay at the initial day and 3 days after storage.The overall aim of this work was to determine the conditions necessary to extend the storage life of partially de-husked Makapuno coconuts after harvest. Our observation of Makapuno coconut maturation agreed with the findings of Islam et al. . Makapuno coconut reached early maturation ∼9 months after flowering and became fully mature ∼10–11 MAF. The endosperm is thicker and softer than that of normal coconut and the liquid endosperm filled the rest of cavity. Our data showed no significant difference in respiration and ethylene production of Makapuno coconut harvested between 9 and 11 MAF .Since there are no published data on the post harvest biology of Makapuno that we are aware of, this work is the first evaluation of the compositional, physiological and biochemical changes in Makapuno coconut fruit after harvest. During 3 days of storage at 30 ◦C, the rates of respiration and ethylene production for Makapuno were similar to those reported for normal mature coconut genotypes . However, the respiration rate from disks of Makapuno coconut was found to be higher than that of intact whole fruit.
This may be due to differences between whole fruit and disks in term of the amount of surface area exposed to the atmosphere or the gas transmission and gas solubility through the tissues. Post harvest fruit quality can be partially assessed by evaluating SS, TA and weight loss. The SS of de-husked normal coconut declines but TA increases as the post harvest storage period increases . Normal harvested mature coconuts lose weight gradually over the storage period due to water evaporation from the fruit cavity or due to absorption by the kernel . In contrast, Makapuno coconut in this study exhibited less weight loss probably due to the viscosity of the endosperm, which restricted water loss through evaporation . Consequently,the color, SS and TA of Makapuno meat did not significantly change after 3 days of 30 ◦C storage. One of the major problems with coconut storage is the increasing rancidity of the endosperm that results from lipid oxidation i.e. the oxidative deterioration of lipids. This leads to an undesirable taste and smell during storage. Malondialdehyde is used as an indicator of lipid peroxidation , and generally, higher MDA levels correlate with higher rancidity . Although insignificant , the MDA of the meat increased 2-fold after 3 days at 30 ◦C storage. Compared to other coconuts, lipid oxidation is less problematic for Makapuno during storage,vertical farming technology probably due to the lower crude fat relative to non-Makapuno types . Another major problem of harvested coconut is decay. Deterioration of Makapuno fruit was evident as mold infestation on the husk surface, which also penetrated the fruit ‘eye’ after they were transferred to 30 ◦C for 3 days . The most prevalent fungal molds found on Makapuno husks were Aspergillus spp. and Penicillium spp. but Fusarium spp. and Curvulria spp. were also detected . Treating fruits with 3–5% sodium metabisulfite or linear low-density polyethylene—file wrap could not prevent surface mold or extend Makapuno coconut storage life when stored at 30 or 5 ◦C .As expected, fruit storage-life increased with decreasing temperature. At 5 ◦C the rate of respiration and ethylene production was reduced 3–6 fold and the storage life was increased to 42 days when stored at 5 ◦C rather than 3 days at 30 ◦C. Moreover, following transfer from 5 to 30 ◦C, respiration rates were similar to fruit kept continuously at 30 ◦C and ethylene production did not change , indicating that there was little or no chilling injury using these temperatures and storage times . During the 6-week storage period, fruit weight loss was significant but endosperm color, SS, TA and decay incidence were similar to those that were stored at 30 ◦C for 3 days. This may indicate that most of weight loss caused by loss of moisture from husk but not from the endosperm. Makapuno fruit developed symptoms consistent with post harvest chilling injury when stored at 2 ◦C for 4 weeks. Cold-stored fruits transferred to 30 ◦C for an additional 3 days exhibited signs of deterioration: the meat developed a woolly texture, and a rancid smell and taste coincided with higher MDA and decay scores. Thus, 2 ◦C was more unsuitable for Makapuno coconut storage than 5 ◦C.Generally, enclosing fruit in films, bags or coatings reduces water loss, prevents the spread of disease among batches of stored fruit and establishes an atmospheric composition that slows down deterioration . It was previously reported that high-OTR bags can enhance the shelf life of mature coconuts . To determine the effect of high-OTR on Makapuno coconuts quality,fruits were stored individually in high OTR bags and kept at 5 ◦C and compared to unbagged fruits held at 5 ◦C.
Coconuts in high-OTR bags had a high O2 transmission rate which allowed O2 to escape from the bag resulting in low O2 accumulation inside. Ethylene also accumulated, but the concentration was lower than 0.15 ppm. While the unbagged Makapuno coconut could be stored only for 6 weeks at 5 ◦C, Makapuno coconut kept in high-OTR bag and stored at 5 ◦C lasted for 10 weeks without any sign of deterioration. In addition, high OTR bag and 5 ◦C storage minimized evaporation very effectively as there was almost no weight loss after 10 weeks and there was no change even after transfer to 30 ◦C for 3 additional days . This reduction in weight loss is likely due to the high relative humidity maintained inside the bag. The combination of high-OTR bag and 5 ◦C effectively suppressed the growth of microbes probably via protecting the coconut from direct contact with fungi and preventing moisture condensation on husk surface. The CO2 and O2 concentration were not high or low enough to kill the fungi therefore it is unlikely that the modified atmosphere would affect fungi pathogen metabolism. The MA provided by the high-OTR bag also maintained SS, TA and MDA levels even after transfer to 30 ◦C. After 10 weeks storage in high OTR bags, fruit quality was maintained and coincided with a reduction in water loss. Thus it is hypothesized that the reduction in water loss might be the most important factor prolonging Makapuno storage life when stored in high OTR bags. However, conclusive proof of this hypothesis requires further experiment.What was once limited to the realm of science fiction and theoretical astrophysics models is now within an operational vision of exploring the “final frontier,” otherwise known as outer space. With the advent of cost-effective launch technologies and the gradual deregulation of space launches and flights, the global economic activity in the space industry has begun to surge. While satellite services likely comprise most viable and profitable venture in space, the adoption of novel space-based goods and services, from space tourism to organ bio-printing, show tremendous potential to disrupt even incumbent industries on Earth. The global space industry has increased in value from $162 billion in 2005 to $469 billion in 2021. While government spending increased 19% to add $107 billion to the space industry, much of the value growth can be attributed to the private sector: commercial enterprises provided an estimated $224 billion in goods and services and $138 billion from constructing infrastructure and support . The most recent space industry reports by Citi and Morgan Stanley project a $1 trillion valuation and $100 billion in annual revenues by 2040 . Space-related research and development has expanded dramatically based on the 22% annual increase for the past five years attributable to the private sector, in contrast to the 10% increase for U.S. governmental expenditures in nominal dollars . While NASA and public sector expenditures have stagnated $12 billion2 in the past few decades, “NewSpace” companies,3 or new companies emerging in the private space industry, have invested an estimated $5-6 billion in 2020, up from less than $1 billion in 2010 .