Unripe Mangoes Research Articles

Mango headspace volatiles trigger differential responses of the mango fruit fly Ceratitis cosyra and its parasitoids

Before the introduction of Bactrocera dorsalis (Hendel) to sub-Saharan Africa, Ceratitis cosyra (Walker) was economically the most important pest in mango farming. Its native natural enemy, the solitary parasitoid Psyttalia cosyrae (Wilkinson), played a crucial role in C. cosyra bio-control, later complemented by the exotic parasitoids Diachasmimorpha longicaudata (Ashmead) and Fopius arisanus (Sonan) among Integrated Pest Management (IPM) systems. To understand the in situ mango-C. cosyra-parasitoid tritrophic interaction, we assessed the responses of the fruit fly and the three parasitoids to headspace volatiles from various mango conditions. These conditions included non-infested mature unripe mangoes, C. cosyra-infested mangoes, 7th- and 9th-day post-infestation mangoes, non-infested ripe mangoes of three varieties (Kent, Apple, and Haden), and clean air (blank). We also compared the fruit fly's performance in the mango varieties and identified the chemical profiles of mango headspace volatiles. Ceratitis cosyra was attracted to both infested and non-infested mangoes (66–84 % of responsive C. cosyra) and showed superior performance in Kent mango (72.1 % of the 287 puparia recovered) compared to Apple and Haden varieties. Fopius arisanus displayed a stronger attraction to the volatiles of C. cosyra-infested mangoes (68–70 %), while P. cosyrae and D. longicaudata were significantly attracted to the 9th-day post-infestation mangoes (68–78 %) compared to non-infested mango volatiles. Gas chromatography-mass spectroscopy showed substantial quantitative and qualitative differences in volatile profiles among mango treatments. Esters predominated in non-infested ripe, 7th- and 9th-day post-infestation mangoes, while monoterpenes and sesquiterpenes were most dominant in the other treatments. The in situ experiments underscored varying preferences of the species for mango headspace volatiles and their subsequent treatments. These results provide valuable insights for further exploration, specifically in identifying the key volatiles responsible for species responses, to facilitate the development of applicable selective semiochemicals for managing species of African fruit fly.

Screening and Characterization of Phenolic Compounds from Selected Unripe Fruits and Their Antioxidant Potential.

The food sector's interest in sustainability and the demand for novel bioactive compounds are increasing. Many fruits are wasted every year before ripening due to various climatic conditions and harsh weather. Unripe mangoes, grapes, and black lemons could be rich sources of phenolic compounds that need to be fully elucidated. Using fruit waste as a source of bioactive chemicals has grown increasingly appealing as it may have significant economic benefits. Polyphenols are beneficial for human health to inhibit or minimize oxidative stress and can be used to develop functional and nutraceutical food products. In this context, this study aimed to characterize and screen unripe mangoes, grapes, and black lemons for phenolic compounds using LC-ESI-QTOF-MS/MS and their antioxidant activities. Unripe mangoes were quantified with higher total phenolic content (TPC, 58.01 ± 6.37 mg GAE/g) compared to black lemon (23.08 ± 2.28 mg GAE/g) and unripe grapes (19.42 ± 1.16 mg GAE/g). Furthermore, unripe mangoes were also measured with higher antioxidant potential than unripe grapes and black lemons. A total of 85 phenolic compounds (70 in black lemons, 49 in unripe grapes, and 68 in unripe mango) were identified, and 23 phenolic compounds were quantified using LC-MS/MS. Procyanidin B2, gallic acid, epicatechin, caffeic acid, quercetin, and chlorogenic acid were measured with higher concentration in these selected unripe fruits. A positive correlation was found between phenolic contents and the antioxidant activities of unripe fruits. Furthermore, chemometric analysis was conducted to validate the results. This study will explore the utilization of these unripe fruits to develop functional and therapeutic foods.

Olfactory Responses of Anastrepha obliqua (Diptera: Tephritidae) to Mango Fruits as Influenced by Cultivar and Ripeness Stages.

Anastrepha obliqua Macquart (Diptera: Tephritidae) is a polyphagous species with hog plums (Spondias spp.) (Sapindales: Anacardiaceae) and mangoes (Mangifera indica L.) (Sapindales: Anacardiaceae) as primary host fruits. In this study, the olfactory preference of A. obliqua for three stages of ripeness of two mango cultivars ('Coche' and 'Ataulfo') was investigated. The female flies were more attracted to ripe 'Coche' fruits compared to those ripe 'Ataulfo'. Further, they were more attracted to the 'Coche' half-ripe and ripe fruits than to the unripe ones, but they did not discriminate among the stages of ripeness of 'Ataulfo' fruits. The male flies did not show preference for any specific mango cultivars or ripeness stage tested. Four compounds from ripe 'Coche' mangoes, and two from ripe 'Ataulfo' fruits were identified using coupled gas chromatography-electroantennographic (GC-EAD) recording and gas chromatography-mass spectrometry (GC-MS) analysis. 'Coche' mango volatiles eliciting responses from the female antennae were ethyl butyrate, ethyl hexanoate, ethyl heptanoate, and ethyl octanoate. The two 'Ataulfo' mango volatiles were identified as 3-carene and ethyl octanoate. These compounds were absent in unripe mangoes of both cultivars. Synthetic blends of these compounds were attractive to females as mango extracts in field cage tests. Our results suggest that the olfactory preference of A. obliqua for attractive hosts is based on the presence or absence of the compounds associated with fruit maturity.

Differential responses of Bactrocera dorsalis and its parasitoids to headspaces of different varieties of tree-attached mango fruits and the associated chemical profiles

Bactrocera dorsalis (Hendel) is a major pest of fruits and vegetables worldwide with documented losses of up to 100%. Various management techniques including the use of parasitoids, such as Fopius arisanus (Sonan) and Diachasmimorpha longicaudata (Ashmead) (Hymenoptera: Braconidae) within the context of the Integrated Pest Management (IPM) approach have been deployed for its control. The effectiveness of parasitoids is well understood, but knowledge of the semiochemicals that mediate their behavior, as well as that of the host fruit fly to tree-attached mangoes, is lacking. Here, we first compared the attractiveness of the above-mentioned fruit fly and its parasitoids to volatiles of different treatments (non-infested physiologically mature unripe and ripe mangoes, mangoes newly exposed to ovipositing B. dorsalis, and mangoes on day 7 and day 9 post-oviposition) of tree-attached Kent, Apple, and Haden mango varieties relative to control (clean air). The fruit fly was significantly more attracted to the mango volatiles (up to 93% of responsive insects) compared to the control (clean air). Fopius arisanus was significantly more attracted to mangoes with ovipositing fruit flies (68–76%) while D. longicaudata was significantly more attracted to day 9 post-oviposited mangoes (64–72%) compared to the control. Secondly, we elucidated the headspace volatile profiles of the non-infested and infested tree-attached mangoes using gas chromatography linked to mass spectrometry (GC-MS). The volatiles revealed various types of organic compounds with qualitative and quantitative differences. The majority of the compounds were esters making 33.8% of the total number, followed by sesquiterpenes-16.4%, and monoterpenes-15.4% among others. Most compounds had higher release rates in headspace volatiles of fruit fly-infested mangoes. Lastly, we harvested the infested mangoes and incubated them for puparia recovery. The number of puparia recovered varied according to the mango variety with Apple mango registering 81.7% of the total, while none was recovered from Kent. These results represent the first report of the changes in the headspace components of non-infested and infested tree-attached mangoes and the associated differential responses of the mentioned insects. A follow-up study can reveal whether there is a convergence in olfactomes which is significant when developing baits that selectively attract the fruit fly and not its natural enemies and fill the knowledge gap from an evolutionary ecological perspective.

Harvest Handling and Postharvest Conditions for Optimum Nutrient Quality in Mango: Minerals and Vitamins

Good practices at harvest and postharvest could be useful in obtaining nutritious mango with high minerals and vitamins. The present study evaluated effect of harvest handling and postharvest conditions on the level of minerals and vitamins using standard methods. Ripe, half-ripe and unripe mangoes were harvested on parent plant and on ground around parent plant. The half-ripe and unripe mangoes were further divided to include heat ripened mangoes. The mango samples were separately stored naturally at 25±3oC and heat ripened at 37±5oC for 0 to 10 day after harvest (dah). The results show Ijebu-Mamu mangoes could cater for reference dietary intake of Vit C. Mango harvested on parent plant has highest level of minerals and vitamins than those picked on ground. Ripe mango has highest level of minerals, half ripe mango presented highest level of vits. B1 and B2 and unripe mango has highest level of Fe and Vit. C. Heat caused increased level of minerals and reduced level of vitamins. The minerals show increased level from 0 to 4 or 6 dah while vitamins reduced from 0 till 10 dah. High level of minerals and vitamins was obtained with optimum integrated harvest and postharvest condition of half-ripe mango naturally ripened at 6 dah. The present results highlight effects of the assessed harvest handling and postharvest conditions and their co-optimization that might be necessary for high minerals and vitamins in mango.

Manyisig: The culinary heritage significance of Sisig in Angeles City, Pampanga, Philippines

Manyisig is a documented word from the Vocabulario de la Lengua Pampanga of Friar Diego Bergano, published in 1860, which means a kind of salad with a spicy vinegar dressing or any sour snack that includes unripe mangoes or guavas. From this context and through the culinary and community development, manyisig became the origin of what is known today as Sisig or chopped, minced pork face and cheek with onions and chilies. This qualitative-case study research explicated the culinary heritage significance of Sisig ni Angeles City, Pampanga, Philippines. It also highlights the common characteristics of Angeles City Sisig, such as raw ingredients, associated tangible and intangible heritages, associated built structures, and culinary tradition. The research assessed the culinary tradition by collecting physical evidence through observation using culinary heritage mapping and photo and video documentation, oral evidence through in-depth interview using semi-structured aide memoire and robofoto, and documentary evidence through content analysis using literature review and synthesis matrix or tabular reconnaissance. A total of forty-six (46) food establishments were documented with their versions of Sisig. In analyzing the information collected, a repertory grid and thematic network analysis were used. Sisig culinary tradition translates on different cultural aspects, such as raw ingredients that are meat-related, fat, flavor enhancer, related or associated, and cultural development, associated tangible heritages that are cooking materials, consumption-related, and food pairing, associated intangible heritages, specifically on the process of cooking, associated built structures that highlight the source of the culinary tradition, viability, and culinary tradition. In conclusion, the Kapampangans, specifically from Angeles City, continuously safeguard and protect the tradition through communal and cultural connectivity.

Edible Coatings as Carriers of Antibrowning Compounds to Maintain Appealing Appearance of Fresh-cut Mango

Fresh-cut mango (Mangifera indica) slices and chunks garner an exotic image and are highly appreciated for their unique flavor and nutritional value. However, processors tend to use firm unripe mangoes to achieve shelf life of 10 to 14 days, which compromises eating quality. The post-processing life of ripe fresh-cut mangoes is limited by tissue softening, translucency, and browning. The current study was undertaken to investigate whether edible coatings can extend the shelf life of fresh-cut mangoes processed at an eating-ripe stage. Three edible coatings, carboxymethylcellulose (1% w/v), aloe (Aloe vera) powder (2% w/v), and whey protein isolate (2% w/v), supplemented with calcium ascorbate 2% w/v (firming agent) and the antioxidants citric acid (0.8% w/v) and acetyl-N-cysteine (0.4% w/v), were used. The mixture of antibrowning agents, whether applied alone or with the edible coatings, was the most effective at reducing slice browning up to 10 and 11 days at 5 °C for ‘Tommy Atkins’ and ‘Kent’, respectively. In general, there were no differences in firmness and flavor among the three edible coatings. Calcium ascorbate alone did not suppress browning consistently, whereas citric acid appeared to be the ingredient having the greatest antibrowning effect on slice quality. Citric acid can easily be used by processors of fresh-cut mangoes to prevent browning.

Pulp and peel of unripe stenospermocarpic mango (Mangifera indica L. cv Ataulfo) as an alternative source of starch, polyphenols and dietary fibre

As a result of climate change, the production of stenospermocarpic mangoes has increased dramatically. The stenospermocarpic mango, a fruit with reduced size and no seed, is considered to be a by-product that is both underutilised and wasted.Here, we studied the colour, chemical composition, polyphenol content, antioxidant capacity and starch in vitro digestibility of unripe stenospermocarpic mango flours (pulp and peel). The stenospermocarpic mango pulp flour had 11.7 g/100 g of dietary fibre with a balance of soluble and insoluble fractions; additionally, the total starch content of 41 g/100 g in its uncooked flour (resistant starch) can contribute to an increase in the indigestible carbohydrates. The mango peel flour had higher dietary fibre (40.5 g/100 g) and lower total starch content (21 g/100 g) compared with mango pulp flour.The mango pulp flour had higher phenolic compounds content (99.71 mg/g) and antioxidant capacity (248.5 mg/g, DPPH) compared with the peel flour (16.51 mg/g and 92.08 mg/g, DPPH), respectively.The rapidly digestible starch fraction was approximately 50%, with a balance in the content of slowly and resistant starch fractions in the mango pulp flour (approximately 20% per fraction).The flours of the pulp and peel of unripe stenospermocarpic mangoes can be used as alternative ingredients for preparing functional foods with high dietary fibre content and polyphenol compounds with antioxidant capacities.

Non-invasive detection of internal flesh breakdown in intact Palmer mangoes using time-domain nuclear magnetic resonance relaxometry

The advent of new compact, bench-top, inexpensive and more user-friendly low-field nuclear magnetic resonance spectrometers in the last decade opens new opportunities for new non-destructive and non-invasive analytical methods to study physical-chemical properties of the internal parts of fruits. Correlations of the internal chemical environment with NMR relaxometry signals is an important parameter for food quality control, however, differently from controlled processed food, internal fruits environment has not always a straight correlation with relaxometry signals. In this paper we demonstrate that Time Domain-NMR signals combined with chemometrics analysis are a powerful tool for studies and industrial control of the internal quality of Palmer mangoes, providing tools to evaluate the fruit ripeness and internal flesh breakdown, which are highly difficult to be detected in intact fruits by other analytical methods. Results shows that combining transverse relaxation time distribution with Principal Component Analysis it is possible to classify three groups: unripe mangoes, ripe mangoes, and ripe mangoes with physiological defects.

Transcriptome-wide identification and characterization of the Rab GTPase family in mango.

The Rab GTPase family plays a vital role in several plant physiological processes including fruit ripening. Fruit softening during ripening involves trafficking of cell wall polymers and enzymes between cellular compartments. Mango, an economically important fruit crop, is known for its delicious taste, exotic flavour and nutritional value. So far, there is a paucity of information on the mango Rab GTPase family. In this study, 23 genes encoding Rab proteins were identified in mango by a comprehensive in silico approach. Sequence alignment and similarity tree analysis with the model plant Arabidopsis as a reference enabled the bona fide assignment of the deduced mango proteins to classify into eight subfamilies. Expression analysis by RNA-Sequencing (RNA-Seq) showed that the Rab genes were differentially expressed in ripe and unripe mangoes suggesting the involvement of vesicle trafficking during ripening. Interaction analysis showed that the proteins involved in vesicle trafficking and cell wall softening were interconnected providing further evidence of the involvement of the Rab GTPases in fruit softening. Correlation analyses showed a significant relationship between the expression level of the RabA3 and RabA4 genes and fruit firmness at the unripe stage of the mango varieties suggesting that the differences in gene expression level might be associated with the contrasting firmness of these varieties. This study will not only provide new insights into the complexity of the ripening-regulated molecular mechanism but also facilitate the identification of potential Rab GTPases to address excessive fruit softening.

Microwave Dielectric Properties for Detection of ‘Harumanis’ Mangoes Ripeness

The qualities of mango are affected by moisture content and storage conditions on fruits stability. Thus, the dielectric properties of maturity stages of mango were studied in this work. The dielectric constant and loss factor were measured using the commercial probe (Agilent 85070E) at microwave frequencies range (0.2 - 5 GHz), whilst the moisture contents were obtained using the standard oven drying method. Comparison results were obtained between the different dielectric and moisture content to predict ripeness of mango. Moisture content values for of mangoes decreased with ripening time. The decreasing tendency was mainly attributed to increased ε’ and ε” values. The prediction mango ripeness can be obtained from measured values of the dielectric constant which obtained ε’ values for unripe (19 - 24), while both ripe and overripe mangoes has similar ε’ range values (16 - 21) at microwave range (0.3 GHz to 5 GHz).

Effect of guar gum coatings containing essential oils on shelf life and nutritional quality of green-unripe mangoes during low temperature storage

This study investigated the effect of treatment of guar gum coating coupled with essential oils. Harvested unripe green mangoes (UGM) were preserved using edible coatings containing essential oils of Nigella sativa, Coriandrum sativum, Foeniculum vulgare and Laurus nobilis derived using two different solvents (methanol and ethanol) and stored at refrigeration temperature (10°C, 80–85% relative humidity). Physiological and biochemical parameters that assess the quality of fruits were determined. Microbiological analysis was also performed at the start and end of shelf life. Generally, it was observed that ethanolic essential oils supplemented coatings conferred a greater retention of fruit quality as compared to both controls. Bacterial counts were significantly reduced in fruits that were coated with ethanolic essential oil edible coatings. Secondly, the coatings supplemented with ethanolic and methanolic essential oils extended shelf life up to 24days whereas treated and untreated control decayed after 10 and 6days respectively (P<0.05). These results suggested the application of these edible coatings for preservation of unripe green mangoes during cold storage.

IMPORTANCE OF AMCHOOR PRODUCTION IN TRIBAL ECONOMY A CASE STUDIES OF AKKALKUWA TAHSIL IN NANDURBAR DISTRICT.

The Tribes Bhil, Pawra, Dhanka, Tadvi Dhanka are known for the production of Amchoor of Satpura ranges in Nandurbar District. They are specially relying on this production. The present paper aims to explore the process of Amchoor production and contribution for source of economy in tribal livelihood. Amchoor production from raw unripe wild mangoes, that are peeled and fresh cut sliced then sun dried. The dried Amchoor is sold in the local market. The Tribes are unknown about the other market subsequently they have to depend on the local market rates and local trader’s policy. The market price is decided by the local traders. The local traders take advantages of their illiteracy and do not pay them the handsome of amount as per the weight and measures. The local traders exploit the producers economically. Amchoor powder has a pleasant sweet-sour aroma of the dried fruits. It has a cooling effect and is good for digestion.

“I eat two meals per day” impact of climate variability on eating habits among households in Rufiji district, Tanzania: a qualitative study

Improved understanding of the influence of climate variability on eating habits is required to manage health outcomes that could be produced. Agriculture production is the main source of income to people in Rufiji district, where communities produce food for household and also for income. Effects of climate variability and weather extremes include occurrence of floods and prolonged dry seasons, which are recently reported to be very frequent in Africa continent, affecting food production. Prolonged dry seasons as well as frequent floods have been reported to destroy cultivated food crops in Rufiji district. However, there is little evidence on climate variability effects on household food security and their eating habits in Tanzania. Therefore, this study assessed the influence of climate variability impacts such as prolonged dry seasons and floods on the eating habits of Tanzanian rural households. Study findings showed that respondents recognized changes in seasonal trends such as rainfall pattern and increase in temperature in the area. Drought and floods reduce food production and cause shortages in households. Low and poor harvest of food crops is the major contributing factor in their farms of rice and maize, the main staple food crops grown amidst prolonged dry seasons. They reported existence of household food shortage which was not there 10 years ago. Participants developed adaptation mechanisms that included reducing food quantity, eating of new meals which were not eaten before as a main meal such as cooked unripe mangoes and stiff porridge. Household members decided to change eating habits as an adaptation strategy to the situation of food shortage. Some discussants acknowledged reducing number of meals, eating two meals a day instead of three or four as it was 10 years ago. Climate variability has led to reduced amount of annual rainfall, thus affecting food productivity and consequently food shortages and changes in dietary habits among the people in Rufiji. Additional research is warranted to assess the impacts of climate variability on nutritional quality of meals.

Impact of ripening stage and drying on selected quality attributes of apple mango cubes and leathers

Apple mango is an improved cultivar that has been widely adopted by farmers in Kenya for use in the fresh market and processing. However, its production and consumption are adversely affected by high postharvest losses, which result from the perishable nature of the fruit, especially during glut periods. This is partly due to limited availability of information on alternative product use. The aim of this study was to evaluate the impact of ripening stage and drying on the physico-chemical quality and sensory acceptability of Apple mango fruit grown in the upper Athi River region of Kenya. Moisture, crude ash, crude fibre, titratable acidity, total soluble solids, colour, total carotenoids and ascorbic acid of the unripe and ripe fresh mangoes were determined. Subsequent experiments involved drying of ripe and unripe mango cubes (8mm) in a windy oven (at 60°C) and, in parallel, drying of ripe mango puree (mixed with sucrose-glucose solution, citric acid and pectin) in a windy oven at three different temperatures (50, 60 and 70C) which resulted in mango leathers. Analysis of total carotenoids, ascorbic acid content and colour was done for all dried samples, followed by sensory evaluation using the nine-point hedonic scale. The moisture content, crude ash and total soluble solids increased significantly (P&lt;0.05) with ripening while titratable acidity decreased significantly (P&lt;0.05). Ascorbic acid content decreased from 98.03 to 86.45 mg/100g with ripening while total carotenoids content approximately doubled from 768 to 1436 μg/100g. Drying resulted in high retention of total carotenoids, whereas, ascorbic acid content decreased. The mango samples became darker and redder in all cases. Dried mango cubes and leathers derived from ripe mangoes had higher scores in the sensory analysis compared to those obtained from unripe mangoes. In conclusion, the stage of ripening and drying technique employed are critical in determining the nutritional and sensory characteristics of dried Apple mango cubes and leathers. Drying Apple mango leathers at 60°C is the best method that can be adopted.

Retention of latex at harvest, enhanced mango (Mangifera indica L.) fruit resistance and reduced anthracnose and stem-end rot

Unripe mangoes contain a network of minute latex canals in its exocarp, outer mesocarp and the pedicel. Latex, when retrieved, separates into an upper oily layer containing antifungal resorcinols and a lower aqueous layer with chitinase activity. Latex disappears in coincidence with ripening and decline of fruit resistance to fungal pathogens. The present study investigated if retention of latex at harvest enhances fruit resistance and reduces anthracnose and the stem-end rot (SER) development during ripening. Latex was retained by harvesting fruit with a portion (approximately 1 cm) of pedicel while in the controls, latex was drained off by removing the pedicel. Anthracnose and SER development from natural infections or following artificial inoculation was assessed at ripe stage. The results showed a significant reduction in the incidence and severity of anthracnose in the cultivar ‘Willard’ susceptible to anthracnose when latex was retained at harvest. There was delayed SER development when latex was retained in the susceptible cultivar ‘Karutha Colomban’. A negative trend was observed between the pedicel length and anthracnose or SER level in cultivars susceptible to the two respective diseases. The fruit peel in which latex was retained had greater chitinase activity. The reduction of anthracnose and SER could be due to the greater resorcinols and chitinase activity respectively in latex-retained fruit. The results indicate a direct involvement of latex in fruit resistance and the possibility of its manipulation to protect ripe fruit from fungal rotting.

CHILLING INJURY IN FRUIT OF THREE MANGO CULTIVARS AND THEIR RELATION TO HYDROGEN PEROXIDE CONTENT AND TOTAL ANTIOXIDANT CAPACITY

Fruit of three mango cultivars representing severe, moderate and slight chilling injury (CI) susceptibility, were stored at 5°C (chilling temperature) and 13°C (recommended storage temperature) for 0, 7, 14, 21, and 28 days. CI symptoms, hydrogen peroxide content and total antioxidant capacity (TAC) were determined both in the peel and the pulp next to the endocarp. 'Nam Dok Mai' mango developed CI in both the peel and the pulp. 'Chok Anan' developed CI only on the peel. No CI was found in 'Hongsawadee'. Mangoes stored at 5°C developed more CI symptoms on the peel than those stored at 13°C. However CI symptom in the pulp was higher at 13°C than at 5°C. After being transferred to room temperature, ripe mangoes developed more peel browning than unripe mangoes. However, lower CI symptom in the pulp was observed. In the peel, 'Nam Dok Mai' was found to have the highest level of total antioxidant capactiy, while 'Chok Anan' had the highest level of hydrogen peroxide. 'Hongsawadee' had the highest level of TAC in its pulp during cold storage but it was found to be the lowest once the fruit were transferred to room temperature. Despite the difference in chilling injury development among cultivars, tissues and ripening stages, no clear relationship between hydrogen peroxide content or TAC level in the three mango cultivars and chilling iniurv could be established.

ADVANCE TECHNIQUE TO PREDICT EATING QUALITY OF RIPE-MANGO AT UNRIPE-STAGE USING NEAR INFRARED SPECTROSCOPY

A technique to predict eating quality, Brix value, of ripe mango from its harvest quality, measured nondestructively by near infrared (NIR) spectroscopy, was successfully developed. The NIR spectra in the short wavelength region (700 to 1100 nm) of unripe mangoes were measured immediately after harvest. Calibration equations for harvest indices, dry matter (DM) and starch content, were developed (SEP: 0.41% w/w for DM, 1.71% w/w for starch). From the NIR spectra measured and the calibration equation developed, the relationship between harvest quality and Brix value at the ripe stage of the same mangoes was revealed. Ripe mangoes would have high Brix value if the fruit contained sufficient amounts of DM and starch at harvest date. Brix value of ripe mangoes could be precisely predicted from the DM and starch measured nondestructively with NIR at harvest. The standard error of prediction (SEP) for the Brix calibration equation was 0.55 °Brix.

Mango ripening—chemical and structural characterization of pectic and hemicellulosic polysaccharides

Ripening of mango is characterized by a gradual, but natural softening of the fruit, which is due to progressive depolymerization of pectic and hemicellulosic polysaccharides with significant loss of galactose, arabinose and mannose residues at the ripe stage. Structural characterization employing permethylation followed by GC–MS analysis, IR and 13C NMR measurements revealed the major CWS fractions of both unripe and ripe mangoes to be of variable molecular weights and having a 1,4-linked galactan/galacturonan backbone, which is occasionally involved in side chain branches consisting of single residues of galactose and arabinose or oligomeric 1,5-linked arabinofuranose residues linked through 1,3-linkages; whereas the major hemicellulosic fractions of unripe mango to be of xyloglucan-type having 1,4-linked glucan backbone with branching by non-reducing terminal arabinose and xylose residues.

Clutch size in frugivorous insects as a function of host firmness: the case of the tephritid fly Anastrepha ludens

Abstract. 1. Optimal clutch size theory predicts that individuals will oviposit the number of eggs that increases their fitness. In Anastrepha ludens Loew (Diptera: Tephritidae), females oviposit larger clutches in unripe (firm) fruits than in ripe (soft) fruits. The following hypotheses were tested: (1) Using fruit firmness as an indicator of fruit quality, A. ludens females vary the number of eggs per clutch every time they reach an oviposition decision. (2) Maximising offspring survival with respect to either unripe or ripe fruit requires placing large clutches in firm fruit and smaller clutches in soft fruit.2. Agar spheres were used as artificial hosts. Three agar concentrations resulted in three degrees of firmness. Mango fruits Mangifera indica L. served as natural hosts. Ripe and unripe fruits were used to test soft and firm host conditions respectively. Females laid significantly larger clutches in the firmer artificial hosts than in the softer hosts. They also laid significantly more eggs in artificial hosts without sugar than in hosts with sugar. Firm (unripe) mangoes also received significantly larger clutches than soft (ripe) mangoes.3. When an individual female was first presented with a firm artificial host, it laid a large clutch. If subsequently offered a soft host, the female laid a significantly smaller clutch. Finally, if again offered a firm host, clutch size was increased significantly.4. Possible trade‐offs in offspring fitness were explored in ripe and unripe mangoes by measuring offspring egg‐to‐adult survival, pupal weight, mean adult longevity, and fecundity. Despite the fact that larval survival was greater in soft fruit than in firm fruit, parameters such as pupal weight, mean longevity, and fecundity of adults stemming from both fruit types did not differ significantly.5. A probable trade‐off between high offspring mortality caused by host unsuitability and low offspring and adult mortality caused by parasitism and predation is discussed as the reason for the exploitation of sub‐optimal hosts.