Commercial techniques for preserving date palm (Phoenix dactylifera) fruit quality and safety: A review

The popularity of date palm (Phoenix dactylifera) fruit is increasing, therefore the demand for high-quality date palm fruit with less or no chemical treatment is the topic of interest for date producers and consumers. The quality of date palm fruit is much dependent on its postharvest handling and processing. For preventing the degradation and maintenance of the high quality of dates during the storage an appropriate harvest and post-harvest processes are required. The process should control the biotic and abiotic factors like insects, fungus, temperature, as well as handling and processing of dates. Therefore, in this work, we reviewed the literature related to the protection of date fruits during their post-harvest life. The commercially viable advance and updated techniques that can be used to avoid storage losses and problems while keeping fruit quality (nutritional, color, flavor, and texture) and microbial safety under optimal conditions are discussed.     

Conservation implications of the mating system of the Pampa Hermosa landrace of peach palm analyzed with microsatellite markers

Peach palm (Bactris gasipaes) is cultivated by many indigenous and traditional communities from Amazonia to Central America for its edible fruits, and is currently important for its heart-of-palm. The objective of this study was to investigate the mating system of peach palm, as this is important for conservation and breeding. Eight microsatellite loci were used to genotype 24 open-pollinated progenies from three populations of the Pampa Hermosa landrace maintained in a progeny trial for genetic improvement. Both the multi-locus outcrossing rates (0.95 to 0.99) and the progeny level multi-locus outcrossing rates (0.9 to 1.0) were high, indicating that peach palm is predominantly allogamous. The outcrossing rates among relatives were significantly different from zero (0.101 to 0.202), providing evidence for considerable biparental inbreeding within populations, probably due to farmers planting seeds of a small number of open-pollinated progenies in the same plot. The correlations of paternity estimates were low (0.051 to 0.112), suggesting a large number of pollen sources (9 to 20) participating in pollination of individual fruit bunches. Effective population size estimates suggest that current germplasm collections are insufficient for long-term ex situ conservation. As with most underutilized crops, on farm conservation is the most important component of an integrated conservation strategy.     

Production of rhamnolipids by a Pseudomonas alcaligenes strain

Brazil is one of the main producers of palm oil (Ellaus guineeusis). It is a low-cost product that has some interesting industrial qualities, such as its use as the raw material for the production of glycerin and soap as well as its use in the preparation of food. Some renewable sources and agroindustrial wastes have been used extensively in research on the production of biosurfactants of the Pseudomonas strains. However, to our knowledge, no studies have been published on the use of palm oil as a substrate for the synthesis of biosurfactants by Pseudomonas alcaligenes. This paper describes the production and characterization of biosurfactants synthesized by a strain of P. alcaligenes PCL previously isolated from soil that was contaminated with crude-oil. Furthermore, the paper presents the optimization of the production of biological surface-active compounds by applying experimental design tools and their capacity to emulsify hydrocarbons.     

A Novel Degenerated Primer Pair Detects Diverse Genes of Acyl Homoserine Lactone Synthetase in Rhizobiaceae Family

A novel degenerated primer set was designed to amplify acyl homoserine lactone (AHL) synthetase genes from members of the family Rhizobiaceae. The primer set successfully amplified AHL synthetase genes from pure cultures of AHL producers from Rhizobiaceae, but not from AHL producers out of the Rhizobiaceae family, indicating the specificity of this primer set to the Rhizobiaceae family. An inoculation experiment showed that the minimal detectable concentration of AHL producers from the soil was around 2.5 × 10⁷ CFU/g soil. When applying to environmental samples, 7 and 14 different genotypes of AHL synthetase genes were identified in the rhizosphere of Glycine max and Vigna unguiculata, respectively, which revealed complicated and unknown AHL-based quorum-sensing networks in the rhizosphere. This is the first primer set that covers diverse AHL synthetase genes from different genera. It will be a useful culture-independent approach for better understanding of the ecological significance of QS in natural habitats.     

Making and marketing Chambira hammocks and bags in the village of Brillo Nuevo, Northeastern Peru

Astrocaryum chambira Burret is a palm that provides edible fruits and fibers for making handicrafts. This study focused on the fiber products (hammocks and bags) made by the Bora in the Peruvian Amazonia. Making chambira handicrafts consists of several different phases. Handicrafts are marketed to tourists, river traders, or shopkeepers in the city of Iquitos. Villagers travel actively to sell their products because of the remote location of the village from the market. The prices received by producers were extremely low when considering the amount of work, but the prices were low also in other steps (middleman, tourist). Still, chambira works provide an important source of income for villagers. The greater abundance ofA. chambira in secondary forest compared with the primary forest indicates that it has potential for agroforestry. Agroforestry systems can provide a sustainable way to use land in the rainforest areas in NE Peru, and in this system nontimber forest products may have an important role.     

Trade in Palm Products in North-Western South America

More than 200 scientific publications and Internet sources dealing with trade in palm products in north-western South America are reviewed. We focus on value chains, trade volumes, prices, and recent developments for some of the most important raw materials derived from native palms. Trade in palm products takes place at local, regional, national, and international levels. For local communities and individual households palm products may play a key role as the most important or only source of cash income. Most of these palm products are inadequately or not at all captured in trade statistics at the local and regional economic levels. Only products such as vegetable ivory and palm heart are monitored statistically, mainly because they are exported. Most raw materials derived from palms are extracted from the wild, and mainly by destructive harvesting. Reduced availability and rising prices on local and regional markets reflect incipient resource depletion. Only in vegetable ivory more or less sustainable wild harvesting methods prevail. Palm heart is increasingly being harvested from orchards and non-sustainable exploitation of wild populations is loosing ground. The international market for native palm oils and pulp (esp. Euterpe oleracea or açaí) is currently served almost exclusively from Brazil. Due to low oil contents and high production costs palm oils are currently used mainly for cosmetics. Based on their content of protein, starch, tocols, and carotenoids palm fruits have high nutritional value and represent a considerable potential for the development of functional foods, food supplements and animal fodder. Palms could undoubtedly play a more important role in the socio-economic development of north-western South America. Sustainability and marketing potential of palm products are negatively affected by the low income obtained by primary producers which often represents no more than 0.01–3% of the retail value. Poor governance, insecurity of land tenure and unequal sharing of profits endanger a sustainable long-term development of these valuable resources.     

Coryphoid palms from the K-Pg boundary of central India and their biogeographical implications: Evidence from megafossil remains

Ten palm leaf impressions are documented from the latest Maastrichtian (late Cretaceous) to early Danian (earliest Paleocene) sediments (K-Pg, c. 66–64 Ma) of the Mandla Lobe of the Deccan Inter-trappean Beds, Madhya Pradesh, central India. The palmate leaf shape along with a definite well-preserved costa support their placement in the subfamily Coryphoideae of the family Arecaceae. We place all recovered palm leaf specimens in the fossil genus Sabalites, report seven species of coryphoid palms and describe two new species namely, Sabalities umariaensis sp. nov. and Sabalites ghughuaensis sp. nov. The fossils indicate that coryphoid palms were highly diverse in central India by the latest Cretaceous. These and earlier reported coryphoid palm fossils from the same locality indicate that they experienced a warm and humid tropical environment during the time of deposition. These discoveries confirm the presence of a diversity of Coryphoideae in Gondwana prior to the India-Eurasia collision and provide information about coryphoid biogeographical history over geological time. Based on megafossil remains, we trace coryphoid palm migration pathways from India to mainland Southeast (SE) Asia and other parts of Asia after the docking of the Indian subcontinent with Eurasia early in the Paleogene.     

An Integrated Hypothesis on the Domestication of Bactris gasipaes

Peach palm (Bactris gasipaes Kunth) has had a central place in the livelihoods of people in the Americas since pre-Columbian times, notably for its edible fruits and multi-purpose wood. The botanical taxon includes both domesticated and wild varieties. Domesticated var gasipaes is believed to derive from one or more of the three wild types of var. chichagui identified today, although the exact dynamics and location of the domestication are still uncertain. Drawing on a combination of molecular and phenotypic diversity data, modeling of past climate suitability and existing literature, we present an integrated hypothesis about peach palm’s domestication. We support a single initial domestication event in south western Amazonia, giving rise to var. chichagui type 3, the putative incipient domesticate. We argue that subsequent dispersal by humans across western Amazonia, and possibly into Central America allowed for secondary domestication events through hybridization with resident wild populations, and differential human selection pressures, resulting in the diversity of present-day landraces. The high phenotypic diversity in the Ecuadorian and northern Peruvian Amazon suggest that human selection of different traits was particularly intense there. While acknowledging the need for further data collection, we believe that our results contribute new insights and tools to understand domestication and dispersal patterns of this important native staple, as well as to plan for its conservation.     

Diversity and occupancy of small carnivores within oil palm plantations in central Sumatra,Indonesia

In Southeast Asia, the conversion of native forests to oil palm plantations threatens tropical biodiversity, but very little is known about the impacts of oil palm cultivation on small carnivore species. To determine the diversity and occupancy of small carnivores within oil palm plantations and to investigate possible factors that might affect their presence within oil palm, we used camera-traps within two oil palm plantations in central Sumatra, analysed the data using occupancy modelling and tested whether two covariates (distance to the edge of the oil palm habitat and distance from extensive areas of lowland forest) affected the model parameters for each small carnivore species. From 3164 camera-trap days, we detected only three small carnivores: leopard cat (Prionailurus bengalensis), common palm civet (Paradoxurus hermaphroditus) and Malay civet (Viverra tangalunga), which indicates that there was a low diversity of small carnivores within the oil palm plantations. Both the leopard cat and common palm civet were found deep within the oil palm, whereas the Malay civet was only detected near the edge in one of the plantations. The leopard cat and common palm civet had very high occupancy values, whereas the Malay civet had low values for both occupancy and detection probability. Neither covariate affected occupancy of the leopard cat and common palm civet, but distance from the edge of the oil palm habitat did influence their detection probabilities. Malay civet occupancy decreased with distance from the oil palm edge, and detection probability was affected by distance from extensive areas of lowland forest. Forests and rest/den site availability are suggested to be important features for small carnivores with oil palm-dominated landscapes.     

An experimental study of the interaction between the dwarf palm (Chamaerops humilis) and its floral visitor Derelomus chamaeropsis throughout the life cycle of the weevil

Palm pollination can be quite diverse but has been poorly studied. This paper describes the life cycle of Derelomus chamaeropsis, a Coleoptera that inhabits the inflorescences of the Mediterranean dwarf palm Chamaerops humilis. D. chamaeropsis is specific to Chamaerops inflorescences, where it eats pollen and the rachis of inflorescences on pistillate plants. They usually lay eggs only on staminate inflorescences where larvae develop and bore into the inflorescence rachis. Larvae do not develop on pistillate inflorescences, except for cases with almost no fruit development. Pistillate plants can thus protect themselves from weevil predation. When visiting pistillate inflorescences, weevils can feed on rachis but usually do not find the brood place reward. Pollination is thus by deceit and weevils should be selected to avoid pistillate inflorescences. D. chamaeropsis pupate within the rachis of staminate inflorescences, but disperse before collecting pollen, thus staminate plants do not have an individual advantage in breeding weevils. However, because larvae develop on dead tissues, the costs of larval development are likely to be low for the plant. This study provides a new example of pollination symbiosis where the pollinator develops on the plant it pollinates, and illustrates how the evolutionary functioning of such relationships can be diverse.     

Staminodes evolution and in vitro development innovation in date palm (Phoenix dactylifera L.)

The in vitro cultivation of date palm staminodes (vestigial stamens) at different stages of female floral ontogenesis confirms the persistence at an immature state of such organs at all the floral differentiation stages. This is evidenced even in fully mature female flowers. Our study revealed the advanced developmental patterns of these rudimentary structures, which bear diverse morphogenetic potentialities. In vitro cultivation of staminodes provides new opportunities for in vitro regeneration of date palm. Such developmental processes were found to be modulated by the stage of floral differentiation, which closely reflected the level of staminode maturity. Development was also impacted by the composition and concentration in plant growth regulators (NAA, BAP and 2,4-D) of the culture media. The large morphogenetic plasticity of the staminodes disposed them to evolutionary variations of the date palm reproduction system. The practical benefits (micropropagation) and the fundamental interests (evolutionary process) of our investigation are discussed.     

TDZ pulsing evaluation on the in vitro morphogenesis of peach palm

Peach palm (Bactris gasipaes Kunth.) cropping is an excellent alternative to native species exploitation; nevertheless, the problems with seed germination and conventional propagation justify the use of in vitro culturing. Aiming to asses TDZ pulsing effect on B. gasipaes morphogenesis, explants obtained from unarmed microplants were maintained in two treatments, half of them in MS free medium (without growth regulator) and the other half in MS with TDZ (0.36 μM). Both groups were transferred to growth regulator-free MS medium following 14 days of culture. After 84 days of culture, TDZ pulsing increased the growth and development of the shoots, restricted the growth and development of the roots, with no influence on adventitious bud induction or somatic embryogenesis. Furthermore, development of prickles, thickening of roots and chlorotic leaves were noted under TDZ pulsing. Leaf sheath histological analysis showed an epidermal origin and no vascularization of these prickles.     

Subsistence benefits from the babassu palm (Orbignya martiana)

Stands of babassu palms (Orbignya martiana) occupy an area of Brazil estimated at nearly 200,000 km², concentrated in the states of Maranhão, Piauí and Goiás. Babassu’s cryptogeal germination, establishing the apical meristem of the plant below ground for its early growth and development, enables it to survive human disturbance, making the palm an integral part of shifting cultivation and pastoral farming systems. People obtain a multitude of products from babassu throughout the palm’s life cycle: leaves are used widely for thatch, basketry, and construction; trunks for palmito and bridges; the fruit for feed, oil and, charcoal. As many as 450,000 subsistence-level households rely on the sale of babassu kernels, used in a regional vegetable oil industry, for an important share of their cash incomes. Deforestation pressures and technological innovation toward an industry based on mechanical processing of whole babassu fruit threaten to reduce benefits the palm provides to the region’s rural poor. Understanding how babassu is used by rural families who depend upon it will help to make current efforts at “domesticating” the palm and whole-fruit processing more responsive to human needs.     

Complete Sequence and Comparative Analysis of the Chloroplast Genome of Coconut Palm (Cocos nucifera)

Coconut, a member of the palm family (Arecaceae), is one of the most economically important trees used by mankind. Despite its diverse morphology, coconut is recognized taxonomically as only a single species (Cocos nucifera L.). There are two major coconut varieties, tall and dwarf, the latter of which displays traits resulting from selection by humans. We report here the complete chloroplast (cp) genome of a dwarf coconut plant, and describe the gene content and organization, inverted repeat fluctuations, repeated sequence structure, and occurrence of RNA editing. Phylogenetic relationships of monocots were inferred based on 47 chloroplast protein-coding genes. Potential nodes for events of gene duplication and pseudogenization related to inverted repeat fluctuation were mapped onto the tree using parsimony criteria. We compare our findings with those from other palm species for which complete cp genome sequences are available.     

Valorization of date palm (Phoenix dactylifera) fruit processing by-products and wastes using bioprocess technology – Review

The date palm Phoenix dactylifera has played an important role in the day-to-day life of the people for the last 7000 years. Today worldwide production, utilization and industrialization of dates are continuously increasing since date fruits have earned great importance in human nutrition owing to their rich content of essential nutrients. Tons of date palm fruit wastes are discarded daily by the date processing industries leading to environmental problems. Wastes such as date pits represent an average of 10% of the date fruits. Thus, there is an urgent need to find suitable applications for this waste. In spite of several studies on date palm cultivation, their utilization and scope for utilizing date fruit in therapeutic applications, very few reviews are available and they are limited to the chemistry and pharmacology of the date fruits and phytochemical composition, nutritional significance and potential health benefits of date fruit consumption. In this context, in the present review the prospects of valorization of these date fruit processing by-products and wastes’ employing fermentation and enzyme processing technologies towards total utilization of this valuable commodity for the production of biofuels, biopolymers, biosurfactants, organic acids, antibiotics, industrial enzymes and other possible industrial chemicals are discussed.     

Reduction of Cell Lysate Viscosity during Processing of Poly(3-Hydroxyalkanoates) by Chromosomal Integration of the Staphylococcal Nuclease Gene in Pseudomonas putida

Poly(3-hydroxyalkanoates) (PHAs) are biodegradable thermoplastics which are accumulated by many bacterial species in the form of intracellular granules and which are thought to serve as reserves of carbon and energy. Pseudomonas putida accumulates a polyester, composed of medium-side-chain 3-hydroxyalkanoic acids, which has excellent film-forming properties. Industrial processing of PHA involves purification of the PHA granules from high-cell-density cultures. After the fermentation process, cells are lysed by homogenization and PHA granules are purified by chemical treatment and repeated washings to yield a PHA latex. Unfortunately, the liberation of chromosomal DNA during lysis causes a dramatic increase in viscosity, which is problematic in the subsequent purification steps. Reduction of the viscosity is generally achieved by the supplementation of commercially available nuclease preparations or by heat treatment; however, both procedures add substantial costs to the process. As a solution to this problem, a nuclease-encoding gene from Staphylococcus aureus was integrated into the genomes of several PHA producers. Staphylococcal nuclease is readily expressed in PHA-producing Pseudomonas strains and is directed to the periplasm, and occasionally to the culture medium, without affecting PHA production or strain stability. During downstream processing, the viscosity of the lysate from a nuclease-integrated Pseudomonas strain was reduced to a level similar to that observed for the wild-type strain after treatment with commercial nuclease. The nuclease gene was also functionally integrated into the chromosomes of other PHA producers, including Ralstonia eutropha.     

Dynamic of reserve compounds of mesocarp and seeds of macaw palm (<Emphasis Type="Italic">Acrocomia aculeata)</Emphasis> submitted to different storage conditions

Key message

Storage changed carbohydrate and protein levels, which can be related to embryo viability. The fatty acid profile was constant, and the embryo composition was similar to the mesocarp, not the endosperm.

Abstract

Macaw palm fruits have a diverse biochemical constitution, and there is significant commercial interest in this species among food, pharmaceutical, cosmetics, and bioenergy industries. We evaluated changes in the reserve compounds of macaw palm mesocarp and seeds from fruits stored for 1 year under three different conditions. Protein and carbohydrate levels were highest in the embryo than in the endosperm. Fatty acid profiles were very similar over time under all storage conditions and in each structure evaluated, with the embryo composition being very similar to the mesocarp. Macaw palm oil remained well preserved under all storage conditions tested, but seed reserves and seed viability are best maintained at room temperatures. The endosperm contained higher levels of saturated fatty acids than either the embryo or mesocarp, making seeds more resistant to oxidative deterioration than the mesocarp. The results showed that the composition of the mesocarp oil promises the production of high-quality biodiesel from this structure, and changes in carbohydrate and protein levels show that laboratory conditions are the most efficient for maintaining seed quality during storage.

     

Population fluctuation of Ephestia figulilella in Kerman province of Iran

Date palm is one of the most important products in Iran. Kerman province is one of the most important producers of this crop. Major areas of date palm cultivation in the province involve Bam, Jiroft and Shahdad. Date palm acreage of Shahdad is over 3500 hectares. Date palm varieties in Shahdad are Ghasb, Shamsaee and Bazmani. Ghasb date palm is most important in Shahdad that is classified as dry product. Date Palm trees have many pests such as the horned beetle dates, spider mite, leafhopper and moths; and according to the studies done in 2008–2009, Ephestia figulilella is the most important pest on fruit dates in Shadad, sometimes 90% of product is contaminated by this pest. This pest has four to five generations per year and overwintered as all of stages in storage and larvae in garden.