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Papaya (Carica papaya L.) is a valuable economic crop that is widely cultivated in tropical and subtropical regions but has a short storage and shelf life. Exploring effective strategies to improve the postharvest quality of papaya is important. This study explored the effect of humidity-triggered controlled-release 1-methylcyclopropene (1-MCP) sheets on the postharvest quality of papaya fruit. 'Rainbow' papayas underwent cold storage at 10 ± 0.5 °C, RH 85% ± 2% for 14 days, and then were transferred to 20 ± 0.5 °C, RH 85% ± 2% for 10 days to simulate shelf life. The 1-MCP sheets were cut into different sizes and placed in storage containers in advance to create corresponding concentrations at 0.5, 1.0, 2.0, and 4.0 ppm. Results showed that 1-MCP treatment inhibited fruit softening, and reduced weight loss and peel color deterioration without causing any physiological disorders. The 1.0–2.0 ppm 1-MCP-treated fruit received the highest score for papaya flavor and sweetness respectively and the lowest score for off-flavor. The humidity-triggered controlled-release 1-MCP sheets are effective and convenient, and they can serve as an important tool for regulating postharvest papaya ripening with economic benefits. [ABSTRACT FROM AUTHOR]

Beverage mixtures based on pineapple (Ananas comosus) and turmeric (Curcuma longa) juice as a ready-to-drink product were developed, and their physicochemical, nutritional, and sensory properties were evaluated. Four different concentrations of turmeric juice (5%, 10%, 15%, and 20% (v/v)) were added to pineapple juice to make turmeric-fortified pineapple (TFP) juice samples. Pineapple juice without turmeric was the control. The L*, a*, b*, titratable acidity (TA), total antioxidant capacity, and %DPPH scavenging values, as well as the concentrations of the phenolic compounds curcumin and demethoxycurcumin, were significantly increased with increasing turmeric concentration. Thirty volatile compounds were detected in the mixed juice samples with turmeric. Most of the turmeric-specific compounds, including monoterpenes, sesquiterpenes and turmerones, were detected in the TFP juice samples. While the antioxidant activity of the juice samples increased with increasing turmeric concentration, the pineapple juice fortified with 10% turmeric (10%T) had the best overall quality as determined by panelists. Greater concentrations of turmeric were associated with decreased palatability due to reduced mouthfeel and sweetness and increased aftertaste and sourness. These results suggest that the 10%T juice could be developed into a commercial functional beverage with increased overall flavor and nutritional quality. [ABSTRACT FROM AUTHOR]

Hibiscus (Hibiscus spp., family Malvaceae) leaves exhibiting symptoms of mosaic, ringspot, and chlorotic spots were collected in 2020 on Oahu, HI. High-throughput sequencing analysis was conducted on ribosomal RNA-depleted composite RNA samples extracted from symptomatic leaves. About 77 million paired-end reads and 161,970 contigs were generated after quality control, trimming, and de novo assembly. Contig annotation with BLASTX/BLASTN searches revealed a sequence (contig 1) resembling the RNA virus, hibiscus chlorotic ringspot virus (genus Betacarmovirus), and one (contig 2) resembling the DNA virus, peanut chlorotic streak virus (genus Soymovirus). Further bioinformatic analyses of the complete viral genome sequences indicated that these viruses, with proposed names of hibiscus betacarmovirus and hibiscus soymovirus, putatively represent new species in the genera Betacarmovirus and Soymovirus, respectively. RT-PCR using specific primers, designed based on the retrieved contigs, coupled with Sanger sequencing, further confirmed the presence of these viruses. An additional 54 hibiscus leaf samples from other locations on Oahu were examined to determine the incidence and distribution of these viruses. [ABSTRACT FROM AUTHOR]

Real‐time and sensitive detection of pathogenic bacteria in food is in high demand to ensure food safety. In this study, a single‐walled carbon nanotubes (SWCNTs)‐based electrochemical impedance immunosensor for on‐site detection of Listeria monocytogenes (L. monocytogenes) was developed. A gold‐plated wire was functionalized using polyethylenimine (PEI), SWCNTs, streptavidin, biotinylated L. monocytogenes antibodies, and bovine serum albumin (BSA). A linear relationship (R2 = 0.982) between the electron transfer resistance measurements and concentrations of L. monocytogenes within the range of 103–108 CFU/ml was observed. In addition, the sensor demonstrated high selectivity towards the target in the presence of other bacterial cells such as Salmonella Typhimurium and Escherichia coli O157:H7. To facilitate the demand for on‐site detection, the sensor was integrated into a smartphone‐controlled biosensor platform, consisting of a compact potentiostat device and a smartphone. The signals from the proposed platform were compared with a conventional potentiostat using the immunosensor interacted with L. monocytogenes (103–105 CFU/ml). The signals obtained with both instruments showed high consistency. Recovery percentages of lettuce homogenate spiked with 103, 104, and 105 CFU/ml of L. monocytogenes obtained with the portable platform were 90.21, 90.44, and 93.69, respectively. The presented on‐site applicable SWCNT‐based immunosensor platform was shown to have a high potential to be used in field settings for food and agricultural applications. Practical Application: The developed immunosensor was developed for on‐site detection of L. monocytogenes. The limit of detection of the sensor was 103 CFU/ml with a detection time of 10 min. In order to facilitate the requirements for effective on‐site screening for food safety, the sensor was integrated into a smartphone‐controlled platform, so that the bio‐molecular interactions were converted into impedance signals and transmitted wirelessly to a smartphone by a hand‐held EIS transducer. [ABSTRACT FROM AUTHOR]

Paprika loses color during storage due to oxidative carotenoid degradation. Ethoxyquin is a synthetic antioxidant used in the spice industry to prevent carotenoid loss, but this is unacceptable in some markets. Naturally derived antioxodants have been tested as color protectants in paprika, including rosemary extracts and ascorbic. The control treatment lost 64% of initial extractable color after 4 months of storage. The delta-tocopheral treated samples lost 32% and the ethoxyquin lost 6%.

BACKGROUND: The coffee berry borer (CBB), Hypothenemus hampei, is the most destructive insect pest of coffee globally, causing significant losses in yield and leading to 'off' flavors in damaged beans. Automated headspace sampling (AHS) and gas chromatography–mass spectrometry (GC–MS) were used to investigate changes in the volatile profiles of CBB‐damaged green coffee beans. Green coffee from three coffee farms on the island of Hawai'i were sorted into three levels of CBB damage: non‐damaged, slightly damaged (1–2 pinholes/bean), and heavily damaged (> 2 pinholes/bean). RESULTS: Distinct differences were found between green coffee bean samples based on the amounts of eight prominent volatiles. The amount of CBB damage was particularly correlated with the amount of both hexanal and 2‐pentylfuran. Principal component analysis showed clustering of non‐damaged green beans, which did not overlap with the slightly or heavily damaged clusters. Good separation was also found between a mixture of 50% slightly damaged and non‐damaged coffee. However, 20% slightly damaged and non‐damaged coffee clusters showed strong overlap. CONCLUSION: Understanding the effects of CBB damage on coffee flavor profiles is critical to quality control for this valuable agricultural product. The results of this study show that the volatile profiles of green coffee beans vary with CBB damage. With specific volatile profiles for CBB‐damaged coffee identified, coffee samples can be tested in the lab, or potentially on the farm or in coffee mills, to identify high levels of CBB damage that may lead to off flavors and a reduction in product quality and value. © 2018 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Abstract: BACKGROUND: Noni fruit (Morinda citrifolia L., Rubiaceae) has been used in traditional medicine throughout the tropics and subtropics and is now attracting interest in western medicine. Fermented noni juice is of particular interest for its promising antitumor activity. The present study collected and analyzed volatiles released at nine time intervals by noni fruit during ripening and fermentation using headspace autosampling coupled to gas chromatography–mass spectrometry. RESULTS: Twenty‐three noni volatiles were identified and relatively quantified. In addition to volatiles previously identified in noni, four novel volatile 3‐methyl‐2/3‐butenyl esters were identified via the synthesis of reference compounds. Principle component analysis (PCA) and canonical discriminant analysis (CDA) were used to facilitate multidimensional pattern recognition. PCA showed that ripening noni fruit cluster into three groups, pre‐ripe, fully ripe (translucent) and fermented, based on released volatiles. CDA could 83.8% correctly classify noni samples when all ripeness stages were analyzed and 100% when samples were classified into the three PCA groupings. CONCLUSION: The results of the present study confirm the identities of 3‐methyl‐2/3‐butenyl esters, both novel and previously identified, through the synthesis of reference compounds. These esters constitute a large percentage of the volatiles released by fully ripe and fermented noni and likely produced from the decomposition of noniosides, a group of unique glucosides present in the fruit. © 2017 Society of Chemical Industry [ABSTRACT FROM AUTHOR]