Optimum Harvest Maturity Research Articles

Sulfur dioxide generating pads containing different concentrations of sodium metabisulfite maintains postharvest quality of ‘Hicaznar’ pomegranate

This study investigated the effects of different sulfur dioxide (SO2) generating pads containing different concentrations of sodium metabisulfite (Na2S2O5) on the storage of ‘Hicaznar’ pomegranate fruit. For this purpose, the pomegranates were harvested at optimal harvest maturity (total soluble solids (TSS): 17.70 %, titratable acidity (TA): 1.57 % citric acid). The first, second and third groups were treated with SO2 generating pads containing different concentrations of Na2S2O5 (1.5, 3.0 and 4.5 g). The fourth group was control which received no treatment. The SO2 generating pads were placed on top of the fruit with butter paper containing holes were kept between the fruit and pads. All the treatments were packaged under modified atmosphere packages (MAP) and stored at 6 °C and 90–95 % relative humidity (RH). The fruit samples for quality analysis were taken at 45, 90, 120, 150 and 180 days (d) of cold storage (CS). Post removal, the samples from each treatment were kept at 20 °C for additional 3 d to determine shelf life (SL) performance of fruit. Extending storage duration showed increase in weight loss, h° values, total flavonoid content, carbon dioxide (CO2) levels and decay index while decrease in L*, C* values, appearance and taste scores, TSS content, TA, total phenolic content, total antioxidant activity, total anthocyanin, ascorbic acid, organic acids (citric, malic, succinic and oxalic acids) contents, phenolic compounds (gallic, protocatechuic and chlorogenic acid), oxygen (O2) levels and SO2 production in MAP. SO2 generating pads reduced weight loss and decay index. The highest taste value was recorded in 3.0 g SO2 generating pads. The highest h° value was in 1.5 g SO2 generating pads while the greatest total anthocyanin content in CS was in 3.0 and 4.5 g with maximum total anthocyanin content in SL was recorded in 1.5 and 4.5 g SO2 generating pads. SO2 generating pads exhibited maximum total phenolic content, total antioxidant activity and gallic acid content as compared to control. There were no SO2 residues in pomegranate arils throughout the storage. It can be concluded that SO2 generating pads can be a potential tool to preserve the postharvest quality of ‘Hicaznar’ pomegranate for 180 d of CS.

Effect of harvesting stage on postharvest quality of black pepper piper nigrum l. cultivars grown in Morogoro, Tanzania

Optimal harvest maturity stage determines the on-shelf quality of black pepper (Piper nigrum L.). Small-scale farmers in Morogoro harvest black pepper before reaching full maturity to catch up with high market prices offered early in the season. Unfortunately, traders are complaining on the quality of black pepper from the area. This study evaluated the effect of harvesting stages on post-harvest quality of pepper cultivars grown in the Morogoro district. Pepper cultivars; Babu kati, Babu kubwa, and Ismailia at premature and mature stages were dried on coconut leaves mats to suitable drying stage. Treatments in a 2 x 3 factorial experiment following a complete randomized design (CRD) were replicated thrice. Statistical significance of variables was generated by ANOVA and mean separation by Tukey HSD test at p ≤ 0.05. Results showed a significant (p<0.001) difference between harvest stages and cultivars on berry colour, moisture content, berry firmness, dry recover and weight loss percentage. Pepper berries at pre-mature stage across cultivars had higher (79.11%) initial moisture content than mature berries (71.6%). Mature berries had higher dry recovery percentage (28.84%) than pre mature (15.78%). Mature “Ismailia” berries had the highest firmness (10.5kg/mm2) than premature (5.8 kg/mm2). During sun drying, colour values L*(brightness), and b* (yellowness) decreased significantly while greenness decreased as a* values increased from more negative values to zero in both harvesting stages as pepper berries darkened. Colour changes were sharper on mature than pre-mature harvested pepper corns. These findings will help farmers to make right decision on when to harvest for quality black pepper product. Farmers are recommended to harvest black pepper when mature for better firmness and colour development during drying. Further studies are required to determine the sensory quality and volatile oil contents of the cultivars when harvested premature and mature stages.

Study on compositional changes of king coconut (<em style="mso-bidi-font-style: normal;">Cocos nucifera </em>var. aurantiaca) water and kernel during maturation  and evaluation of optimum quality characteristics targeting commercial applications

King coconut (Cocos nucifera var. aurantiaca) is a tropical nut with notable nutritional and medicinal values. King coconut water (KCW) and king coconut kernel (KCK) are sweet and refreshing. They undergo several changes during maturation. The objective of this study was to assess the physico-chemical changes of KCW and KCK with maturity. Three different maturity stages (6, 7, and 8 months) of the variety aurantica, known locally as ‘Nawasi Thembili’ were studied for several physico-chemical parameters. Whole nut weight (g), nut-circumference (cm), colour (water/kernel) (*L), nut-water volume (mL), kernel weight (g), and kernel thickness (mm) were assessed as physical parameters, while pH, total soluble solids (oBrix), titratable acidity (as % ascorbic acid), total sugars (g/100g; g/100mL), and minerals (mg/L; mg/kg) were analysed as chemical attributes. Sugars were estimated using Agilent 1260 HPLC and ICP-MS was used to measure the mineral profile. Results revealed that all the tested physical parameters of KCW and KCK increased significantly (p < 0.05) with maturity. The pH, TSS, total sugars, and acidity of KCW increased significantly (p < 0.05), while mineral content decreased significantly (p < 0.05) with maturity. However, the TSS and minerals of KCK decreased significantly (p < 0.05) with maturity and a higher sucrose content was reported in KCK compared to KCW at later maturity. The Ca+2 and Mg+2 were prominent in both KCW and KCK. The study concluded that the physico-chemical characteristics varied widely with the maturity of king coconuts. The selection of optimum harvest maturity to match the preferred attributes of intended applications is suggested.

Fruit colour progression in grapefruit with relation to carotenoid and Brix-acid ratio

In citrus, fruit colouration is considered one of the criteria to assess the optimum harvest maturity. The present study the fruit colour variations, β-carotene and its relation to soluble Brix/acid ratio (B/A ratio) during development in four grapefruit varieties viz. Marsh Seedless, Flame, Rio Red and Redblush were investigated. Among different grapefruit varieties, the highest peel colour coordinate a* value and β-carotene content were recorded in cv. Flame at 270 days after full bloom (DAFS). The peel β-carotene concentration varied from 3.61 to 61.42 μg.g-1 during fruit development. L*coordinate showed a declining pattern in the pulp, while it increased in peel till 270 DAFS. Likewise, b* values also increased in both peel and pulp. Chroma (C*) and B/A ratio values of fruit increased with maturity, while the hue angle (h°) decreased. L*a*b*colour coordinates showed a strong correlation with B/A ratio compared to β-carotene content. At the final fruit harvest, the higher value for L* coordinate in peel and pulp was noted in ‘Redblush’ and ‘Marsh Seedless’. In contrast, the highest b* coordinate was observed in the peel and pulp of the Marsh Seedless variety. Overall, a* coordinate was observed to be the most reliable colour parameter to determine the maturity index in the studied varieties of grapefruit.

Harvest maturity highly affects fruit quality attributes of ethylene-treated ‘autumn sense’ hardy kiwifruit

Optimal harvest date is an important quality parameter for hardy kiwifruit. We, therefore, examined the ideal harvest date to obtain high-quality ripe “Autumn sense” hardy kiwifruit. The fruit was harvested at four different harvest maturity stages [6.2%, 7.1%, 8.1%, and 9.1% average soluble solids content (SSC); H1, H2, H3, and H4, respectively], then treated with exogenous ethylene at ambient temperature, to examine the quality of the ripening fruit. The four harvest maturity stages differed significantly in firmness, SSC, titratable acidity (TA), and SSC/TA ratio, both in freshly harvested and ripe hardy kiwifruit (p < 0.001). Fruit firmness at harvest gradually decreased from 32.1 to 25.1 N, while SSC increased steadily as harvest maturity increased. TA increased steadily from 0.8 in H1 to 1.1% in H3, and was lower in H4. After ethylene treatment, the range of firmness was much lower, at 2.7–3.1 N, while SSC increased significantly from 15.1% in H1 to 16.4% in H4. TA decreased significantly from 1.0% at harvest to 0.7% after ethylene treatment, regardless of harvest maturity stage. For H3 fruit, TA was 56% lower after ethylene treatment than before treatment. After treatment, H3 had the highest SSC/TA (p < 0.001). Consumer preference was higher for H3 and H4 than H1 and H2, and was highly correlated with the SSC/TA ratio at harvest and after ethylene treatment, and with SSC at harvest. These results suggest that TA, SSC, and SSC/TA should be considered for determining the optimal harvest maturity for hardy kiwifruit. This study reveals that the quality of ripened hardy kiwifruit can be maximized by controlling harvest maturity.

A Feasibility Study for a Smartphone-Based Vibratory Bowl System for Peanut Sorting

HighlightsConventional peanut sorting and harvest day prediction were time-consuming and inefficient.A smartphone-based vibratory bowl system was fabricated for fast peanut sorting.The system could transport and sort 200 peanuts in less than 5 minutes.The accuracy of peanut counting was greater than 87%, and the accuracy of color detection was greater than 90%.Abstract. Peanut is an important crop in the southern region of the United States. The southeastern states of Georgia, Florida, and Alabama account for over two-thirds of peanut production. Determining an optimum harvest maturity for peanuts is critical to the industry because it directly impacts the yield and quality of the peanuts. The conventional way of determining peanut maturity is a visual inspection method that could take a long time to generate unreliable and inconsistent results due to human errors. In this study, a new method of determining peanut harvest time was proposed. The black peanuts, which is a class of ready-to-pick one, were selected through an automated process. The machine consists of two processes. The transport process used a mechanism of bowl vibration to align the peanuts into a line before entering the second process-the automated sorter, which would separate the peanuts according to their maturity level. Base on the transport analysis, the vibrational bowl was able to transport 200 peanuts to the automated sorter for less than 5 minutes. As for the sorting process, the experimental results showed the accuracy of peanut counting was more than 87%. The average F1 score for peanut color sorting was greater than 90%. All the findings suggested it is feasible to use a smartphone-based vibratory bowl system for fast peanut counting and color sorting. Keywords: Dynamic color detection, Image processing, Peanut maturity, Vibrational bowl.

Mecitözü (Çorum) Ekolojisinde Yetiştirilen Bazı Üzüm Çeşitlerinin Performanslarının Araştırılması

Bu araştırmada, Mecitözü (Çorum) koşullarında yetiştirilen dört üzüm çeşidinin (Hasandede, Öküzgözü, Boğazkere ve Horoz Karası) optimum hasat zamanları, salkım ve tane özellikleri saptanmıştır. Ardışık iki yıl (2017-2018) boyunca verim, salkım, tane özellikleri, şırada suda çözünebilir kuru madde, pH, titre edilebilir asitlik, olgunluk indisi özellikleri belirlenmiştir. İkinci yıl olgunlaşma dönemlerinde üzüm çeşitlerinde bazı biyokimyasal değişiklikler izlenmiştir. İki yılda da en yüksek verim Horoz Karası (1421,2 ve 1504,8 kg / da) çeşidinde, en düşük verim ise Öküzgözü çeşidinde (619,4 ve 578,31 kg / da) elde edilmiştir. Hasat döneminde, şırada toplam asitlik ve pH değerleri yıllara ve çeşitlere göre değişmiştir. Ben düşme döneminden itibaren olgunlaşmaya kadar tüm çeşitlerde SÇKM ve pH değeri artarken, toplam asit miktarı ise azalmıştır. Hasat döneminde tüm çeşitler her iki yılda da optimum hasat olgunluğuna ulaşmışlardır.

Optimum Harvest of Low-chill Melting and Non-melting Flesh Peach Cultivars for Direct Ripening and Ripening following Low Temperature Storage

The physical and chemical characteristics of two melting flesh (MF) cultivars, TropicBeauty and Flordaprince, and two non-melting flesh (NMF) cultivars, UFSun and Gulfking, with advancing maturities, were determined at harvest, after ripening at 20 °C for 7 days (i.e., direct ripening) and after storage at 0 °C for 14 days then ripening at 20 °C for 7 days (i.e., ripening following low temperature storage). The NMF cultivars were able to retain flesh firmness better than the MF cultivars as fruit matured and ripened on the tree and after the two storage treatments. The NMF fruit of the least mature to the most advanced maturity groups (MGs) were ≈2 to 7 times firmer than the MF fruit in the same MGs after ripening in both storage conditions. For both MF and NMF fruit, a significant reduction of titratable acidity (TA) occurred with no significant changes in soluble solids content (SSC) and total soluble sugar (TSS) as maturity and ripening progressed on the tree and after ripening in both storage conditions. Minimum quality standards of “ready for consumption” peaches were used as general guidelines to determine the optimum harvest maturity of all four cultivars. The NMF fruit ripened directly had wider optimum harvest maturity ranges and could be harvested at more advanced stages than the MF fruit. The MF fruit that ripened following low temperature storage needed to be picked at earlier maturity stages than those that were directly ripened. The optimum harvest maturity of NMF UFSun for the low temperature storage treatment was more advanced than that of the other three cultivars due to abnormal softening found in the lower MGs after ripening. Linear correlation analyses showed that the skin ground color (GC) a* values of both MF cultivars and NMF ‘UFSun’ were highly correlated with the flesh color (FC) a* values, suggesting that GC a* values can be an informative harvest indicator for this NMF cultivar instead of the traditionally used FC. The GC a* values also had high linear correlation with TA for all four cultivars, suggesting that TA can be a potential maturity index for both MF and NMF peaches. Significant correlations of GC a* values and flesh firmness (GC-FF) were found in all four cultivars in one year but only in MF peaches in both years, showing that flesh firmness was the most consistent maturity indicator for the MF cultivars in this study.

An optimal harvest maturity model for ‘Minneiska’ apple fruit based on the delta-absorbance meter

ABSTRACT A hand-held, chlorophyll content meter [the delta absorbance (DA) meter] was used to develop an optimal harvest maturity model for ‘Minneiska’ apples (Malus domestica Borkh). Fruit from four commercial orchards in the Annapolis Valley, Nova Scotia, Canada, were sampled weekly (25 fruit per location) over eight consecutive harvests during the 2011–2013 growing seasons. At each harvest, 60 fruit were measured for their DA value (IAD ), mass, firmness, titratable acidity (TA), soluble solids content (SSC), red skin colouration, starch-to-sugar conversion and internal core ethylene concentration. Following 3–3.5 months of refrigerated air storage at 3.5°C, samples were removed and assessed for fruit bruising, skin greasiness, rot and physiological disorders. Peel chlorophyll content was strongly and positively correlated with epidermal IAD measurements. IAD values declined significantly during fruit ripening and were negatively related to harvest week. The optimal harvest period was identified by aligning ‘at harvest’ IAD , fruit quality and ‘post-storage’ disorder data with the corresponding harvest week. IAD averages associated with harvests having high commercial fruit quality demarcated the optimal harvest boundaries. As the IAD values declined during fruit maturity, the upper boundary value of 0.26 was defined as ‘when to begin harvest’, while the lower boundary value of 0.12 was deemed ‘when to end harvest’ for longer-term storage.

Non-destructive quality assessment of tomato fruit using differential absorbance technique

A rapid and non-destructive assessment of quality parameters in tomatoes was evaluated using a portable differential absorbance (DA) meter in order to accurately establish optimum harvest maturity. A commercial tomato variety cv. ‘BARI Tomato-8’ grown in the summer season of Bangladesh was used in this study. Different quality parameters including fruit skin colour, tissue firmness, chlorophyll contents, ascorbic acid, total soluble solids (TSS), titratable acidity and pH of tomatoes were determined using standard reference methods. Correlation analysis was performed to determine the relationship between the difference in absorbance index (IDA) and fruit quality parameters. The correlation coefficients showed good ability in estimating the hue angle, chlorophyll contents, titratable acidity and firmness of tomatoes showing ‘r’ values of 0.93, 0.91, 0.91 and 0.92-0.94, respectively. However, the changes of ascorbic acid contents and TSS of tomatoes did not follow the linear model during fruit maturation. Thus, the DA meter could most accurately predict the major quality attributes and may be used as an efficient technique for in-plant non-destructive assessment of tomato fruit qualities.&#x0D; Int. J. Agril. Res. Innov. Tech. 9(2): 42-50, December 2019

Maturity stages affect nutritional quality and storability of tomato cultivars

ABSTRACTThis research was conducted to identify the optimum harvest maturity stage/s that yielded the highest nutritional quality and longest marketable shelf-life. “TY Megaton” and “Yureka” cultivars were harvested at the breaker, pink, and red stages and stored up to 20 days at 12°C with 85 ± 5% relative humidity (RH). Quality attributes, the contents of important secondary metabolites, and antioxidant activity were assessed during the storage period. Storing and marketing of tomato fruits up to 3 weeks could be possible. However, a gradually decreasing trend of ascorbic acid and total phenolic content was observed as the maturity stage and storage period proceeded, irrespective of the cultivar. Results of lycopene content and antioxidant activity suggest that better nutritional benefit from the breaker and pink stages could be obtained after 16 and 12 days of storage, respectively, and from the beginning to eighth day of storage for the red stage.

Optimum harvest maturity in relation to its physico-chemical quality of pollinated soursop (Annona muricataL.) fruit

Optimum harvest maturity in relation to its physico-chemical quality of pollinated soursop (<i>Annona muricata</i>L.) fruit

Pod Maturity in the Shelling Process

ABSTRACT Determining an optimum harvest maturity for indeterminate crops such as peanut is critical because it directly affects yield and grade. Historically, the assumption has been that growers will harvest at optimum maturity due to the positive impact on these two characteristics. However, the increased acreage under management by a single farmer may cause growers to harvest prior to optimum maturity. The impact of peanut maturity on seed quality may not be fully understood by producers, where immature seed may have reduced emergence and vigor. Research was conducted to quantify the maturity of seed peanuts received by the Florida Foundation Seed Producers, Inc. (FFSP) at various stages of the shelling process: samples received from the field; after the in-shell samples were cleaned; after in-shell pre-sizing into two size classes; and after separation of in-shell samples at the gravity deck. Samples collected at each stage were pressure-washed to remove the exocarp and then separated into yellow and brown/black color classes based on the maturity board. Pods within each color class were counted, dried, weighed, and graded. Maturity at each sheller stage was assessed for three peanut cultivars. For the field stage, across all cultivars, 56% of pods were in the mature, or brown/black color class. This was well below the level of 70-80% in the brown/black class purported to be the maturity level that optimizes yield and grade. Cleaning had a minor impact on maturity percentages (average percent mature was 64% across all cultivars after passing through the mechanical cleaning process); however, in the pre-shelling sizing process where pods are sorted into “lead” and “small” baskets representing large and small pods, respectively, the maturity percentage was improved to 75% in the large pods and declined to 45% in the small pods. These results indicate that: 1) maturity levels of cultivars harvested in the field may not be optimal; and 2) that improvements could be made in maturity percentages by modifying the shelling process to separate the larger pods which are more likely to be mature than the smaller pods. These results also suggest that seed peanut lots are unlikely to be composed entirely of mature pods, that large numbers of immature pods could make it through the shelling process and that immature seed are planted by farmers. This could explain some cases of suboptimal plant stands in peanut.

On-tree maturity control of peach cultivars: Comparison between destructive and nondestructive harvest indices

Optimal harvest maturity is required for flavorful peach. The supply chain often errs on the side of immature fruit with subsequent consumer dissatisfaction. Maturity indices used to determine harvest date of peach include nondestructive assessments of size and background color, and destructive measurements of flesh color, firmness and soluble solids content (SSC) . More recently an index related to the absorbance of chlorophyll (IAD) can be nondestructively assessed with a DA-meter. This application is particularly useful in red-skinned cultivars in which background color changes from green to yellow are not perceptible to the naked eye. The objective and nondestructive IAD was compared with objective and destructive assessments of firmness and SSC, as indices to make harvest decisions on peach orchards. Seven peach and five nectarine cultivars [Prunus persica (L.) Batsch] were studied. Fruits were assessed with a DA-meter and the resulting IAD values were related to firmness and SSC in several consecutive samplings during the maturity period for each cultivar. Pooling all sampling dates for each cultivar, significant positive linear regressions were observed between IAD and firmness, with coefficients of determination 0.11<R2<0.65. However, in each cultivar the linear regression parameters between IAD and firmness are different and changed in sequential samplings required for maturity control and in successive harvests. No significant relationship was observed between IAD and SSC in any cultivar. In conclusion, the DA-meter cannot replace firmness and SSC measurements during on-tree maturity control, which remain essential for sensory quality management in the supply chain. .

Asynchronous ripening behavior of cactus pear (Opuntia ficus-indica) cultivars with respect to physicochemical and physiological attributes

Physicochemical and physiological ripening events in cactus pear (Opuntia ficus-indica) fruit of cultivars ‘Ntopia’ and ‘Hercules’ were profiled against skin coloration from mature-green (S1) to over-mature (S5). Fructose and glucose accumulation were linear in ‘Ntopia’ but peaked near S3 in ‘Hercules’ synchronously to the appearance of sucrose. Betalains increased steadily in ‘Ntopia’ (103.2mg/l) but peaked before full skin coloration in ‘Hercules’ (49.7mg/l); whereas phenolic content remained invariable and ascorbate content peaked near S5 in both ‘Ntopia’ (108.6μg/g) and ‘Hercules’ (163.1μg/g). Cell wall material diminished with maturity though textural changes with ripening appeared not related to pectin solubilization but to weakening of glycan bonding and loss of neutral sugars. Fruit firmness rather was correlated to seed weight (r=0.89) and seed-to-pulp ratio (r=0.73). Cultivar differences highlighted in the chronology of ripening events are critical for defining optimum harvest maturity and postharvest handling protocols for premium quality cactus pear fruit.

Determination of optimal harvest boundaries for ‘Ambrosia’ apple fruit using a delta-absorbance meter

ABSTRACTIn this study, a new chlorophyll measurement tool, the delta absorbance (DA) meter, was used to develop an optimal harvest maturity model for ‘Ambrosia’ apple (Malus × domestica Borkh.) fruit. Fruit from four commercial orchards in the Annapolis Valley, Nova Scotia, Canada, were sampled (25 fruit from three or four trees per location) over nine consecutive weekly harvests during the 2011 and 2012 growing seasons, and 8 weeks in the 2013 season. At each harvest, five fruit from each orchard site had their index of absorbance difference (IAD) values, firmness, mass, titratable acidity (TA), soluble solids content (SSC), red skin colouration and internal core ethylene concentrations measured. Following approx. 3 months of storage at 3.5°C, 20 fruit from each site were removed and assessed for the incidence of disorders such as senescent breakdown, cortical browning and coreflush. Chlorophyll concentrations in the epidermis were strongly and positively related to IAD values in the same tissue (P ≤ 0.001), confirming the assumption that chlorophyll was the basis for the DA meter IAD signal. In addition, IAD values declined significantly during fruit maturity and were negatively related to harvest week (P ≤ 0.001). The optimum harvest period was identified by aligning all ‘at harvest’ IAD values, fruit quality measurements, and ‘post-storage’ disorder data with the corresponding harvest week. IAD values associated with harvests having the highest commercial fruit quality then delineated the optimal harvest boundaries. The upper boundary IAD value of 0.47 was defined as ‘when to begin harvest’, while the lower boundary IAD value of 0.28 was considered to be ‘when to end harvest’ for long-term storage. The use of a DA meter and its IAD value to define the optimal harvest boundaries may be applicable to all commercial apple cultivars, but should be developed for each cultivar and growing region.

Optimizing the harvest date for long-term storage of ‘Spadona’ pears (Pyrus communis L.) by prediction of the pre-climacteric minimum

The changes in ripening parameters of ‘Spadona’ pears were monitored from 95 days after full bloom (DAFB) until the end of the harvest season in 2 orchards during 3 years, in an attempt to predict the timing of the pre-climacteric minimum (PCM), as a tool for determining the optimum harvest maturity for extended controlled atmosphere (CA) storage.A model based on the pre-harvest rates of changes of fruit weight, firmness, starch degradation and seed colour was found to predict the timing of the PCM with an accuracy of 24h of its occurrence (R2=0.9925). Changes in soluble solid content (SSC) and titratable acidity (TA) did not improve the model. Fruit quality assessed at removal from CA storage after 6 months, followed by 2 weeks of shelf-life at 20°C, verified that the optimal time for harvest of ‘Spadona’ pears was at the PCM.

A Review of Destructive and Non-destructive Methods for Determining Avocado Fruit Maturity

Optimum harvest maturity is one of the important factors determining the quality of avocado fruit. Currently, avocado harvest maturity is mostly determined using markers or indices such as mesocarp oil, dry matter, or moisture content, all quantified destructively using representative samples of a batch in a consignment. Although useful, destructive techniques are time-consuming and results reflect properties of specific produce evaluated. High variation in maturity stages affect postharvest quality and the rate of ripening within a consignment, causing logistical difficulties. Emerging analytical techniques have particular advantages in non-destructive detection of food quality and safety. In this paper, destructive and non-destructive analytical methods and instruments for determining maturity parameters of avocado fruit are discussed. This review also looks at the trends in applying emerging optical and imaging techniques to the analysis of avocado fruit maturity and quality, in particular, visible to near infrared spectroscopy, ultrasonic system, ultrasound imaging, hyperspectral imaging, magnetic resonance imaging, and fluorescence imaging. On the basis of the observed trends, the technical challenges and future prospects for commercial application of these non-destructive techniques for maturity determination of individual avocado fruit are presented.

Kernel Carbohydrates Concentration in Sugary-1, Sugary Enhanced and Shrunken Sweet Corn Kernels

Abstract Sweet corn remains at its optimum harvest maturity for a very short period, and quality changes rapidly following its peak. This study investigates the changes in carbohydrate concentration of three genotypes of sweet corn: sugary ( su-1 ), sugar enhanced ( se ) and supersweet or shrunken ( sh2 ) at three stages of maturity. The analysis of variance revealed differences between genotypes for carbohydrates (sugars and starch) and between stages of maturity (moisture content). Average sugar concentration of su-1 corn was 5% higher than that of se corn and 52% higher than that of sh2 corn. The average starch concentration of su-1 corn was 27% lower than that of se corn and 66% lower than that of sh2 corn. The average moisture content of su-1 corn was 3% lower than that of se corn and 1% lower than that of sh2 corn.

Varietal and harvesting time effects on physical characteristics and sensory attributes of boiled fresh yellow maize hybrids

Objective : The present study evaluated the effect of varieties and harvesting time on the physical characteristics and acceptability of boiled fresh yellow maize hybrids. Methodology and Results: Freshly harvested cobs from eight biofortified yellow maize hybrids, at three harvesting time (20, 27 and 34 days after pollination (DAP)), were used for the present study. The fresh yellow maize ears at each of the harvesting time were boiled without husk in water at 100 o C for averagely 15mins (20DAP), 25mins (27DAP) and 32mins (34DAP) respectively using atmospheric cooking method. Sensory evaluation was carried out on the boiled fresh yellow maize samples within 24 hours after harvesting. The physical characteristics of the fresh maize grains were also determined. Variety and harvesting time had significant effects (P?0.001) on most of the physical properties, except porosity. The optimum harvest maturity stage to consume boiled maize hybrids was found to be 20DAP. There was negative but significant correlation between the physical characteristics and the sensory properties except colour that showed positive correlation. Conclusions and application of findings : Differences in kernel characteristics caused by genetic inheritance and harvesting time can influence the processing, utilization and consumer appreciation of maize. The information from this study could used by the Maize breeders to further improve the physical characteristics of the maize hybrids and by the maize consumers to know the best harvest time to consume boiled maize hybrids Keywords : yellow maize, hybrids, harvesting time, boiled, physical characteristics acceptability