scholarly journals Electrochemical Glucose Quantification as a Strategy for Ethanolic Fermentation Monitoring

Chemosensors ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 14 ◽  
Author(s):  
Isabel Acevedo-Restrepo ◽  
Lucas Blandón-Naranjo ◽  
Jorge Hoyos-Arbeláez ◽  
Flavio Della Pelle ◽  
Mario Vázquez

The possibility of using an electrochemical biosensor, using screen-printed electrodes modified with a carbonaceous material and a commercial kit for the determination of glucose, to monitor an ethanolic fermentation was analyzed. The determination is based on the electrochemical oxidation reaction of NADH that occurs at a potential where the components of the kit do not generate a current signal, even in the presence of the fermentation medium. The electrochemical system was used to analyze the variation of glucose concentration during a laboratory-scale fermentation. The results were contrasted with the variation of standard characterization parameters such as pH, total soluble solids (TSS), the viability of the yeast, and concentration of ethanol produced. Of these values, the total soluble solids should be related to the concentration of glucose obtained by the electrochemical sensor, however, this last measure is more specific for sugar since the TSS refers to all soluble solids. The obtained results allow us to verify the usefulness of the electrochemical method for real-time monitoring of a fermentation.

2020 ◽  
Vol 38 (2) ◽  
pp. 160-165
Author(s):  
Manuella Candéo ◽  
Maria Helene G Canteri ◽  
Dayana Carla de Macedo ◽  
Evaldo T Kubaski ◽  
Sergio M Tebcherani

ABSTRACT Plastic packaging from petroleum derives used in the food industry represents serious environmental problems. Alternative solutions to these problems consist of the development of biodegradable packaging, such as films and edible coatings including the polyvinyl alcohol (PVA). In this research we evaluated the effect of the PVA application by two different techniques aiming to increase shelf life of ripe tomatoes, cultivar Carmen. The methodology of this study consisted in covering tomatoes with a PVA solution and also with PVA impregnated tracing paper. The different fruit lots were kept in polystyrene trays for 19 days on a laboratory bench at a controlled temperature of 25±3ºC. The fruit analyzes were compared to the control fruits without any treatment, being evaluated firmness, pH, titratable total acidity, mass loss, total soluble solids content, water activity and color determination of fruit surface. Among the different treatments, the PVA coating applied directly to the fruits contributed to control the firmness and the mass loss, as well as this treatment influenced the total soluble solids content, the luminosity and the red color of fruits with statistical difference compared to the control and covered with tracing paper (with or without PVA). The PVA coating solution applied directly on the fruits contributed to maintain the postharvest quality of the ripe tomatoes.


Author(s):  
Kongaphisith Tongpoolsomjit ◽  
François Grandmottet ◽  
Ratri Boonruangrod ◽  
Akharapong Krueajan, Jarupa Viyoch

Musa AA ‘Kluai Khai’ banana, is an important economic crop in Thailand. It was evaluated according to its morphology, total soluble solids (TSS), and pulp b-carotene content over different months according to its ripening state. The climate variability of Thailand in 2019 resulted in smaller bananas in May than in other months (March and July). TSS was found to be a directly proportional correlation to the ripening stage. The genotype and ploidy of Musa AA ‘Kluai Khai’ were confirmed using molecular markers and flow cytometry. The yellowish pigment of carotenoid was extracted from banana pulp using THF:MeOH (1:1, v/v). The utilization of HPLC displayed b-carotene content in Musa AA ‘Kluai Khai’ pulp as high as 5222.6 ± 83.8 µg / 100 g of fresh weight (gfw) in the 4th state of banana development in March, which was higher than those in July (4072.8 µg/ 100 gfw) and May (3121.8 µg/ 100 gfw) for the same ripening state. The relationship between b-carotene content and the ripening state was calculated to be a logarithmic correlation.


2005 ◽  
Vol 48 (1) ◽  
pp. 229-234 ◽  
Author(s):  
Y. B. Ying ◽  
Y. D. Liu ◽  
J. P. Wang ◽  
X. P. Fu ◽  
Y. B. Li

2019 ◽  
Vol 15 (2) ◽  
pp. 101-105
Author(s):  
Makful Makful ◽  
Kuswandi Kuswandi ◽  
Sahlan Sahlan ◽  
Mega Andini

Hybrid breeding of watermelon has led to the formation of high-yielding varieties. The objectives of the research were to determine the performance of hybrid watermelon of the Indonesian Tropical Fruit Research Institute (ITFRI) collection and to evaluate the superiority of each hybrid. The research has been conducted at Sumani Experimental Garden, ITFRI, Solok, West Sumatera, from April to July 2016. The material used consisted of 19 cross combinations. The data from this descriptive study were presented in the form of averages and pictures. The results showed that the hybrids that were tested showed diversity in size, fruit skin color, flesh color, skin thickness and fruit sweetness. Hybrids with three excellent characters, i.e. medium fruit weight, high total soluble solids (TSS) value, and moderate rind thickness, were not yet obtained. Hybrids that had the superiority in term of sweet taste and shelf life were BT1 × SGP, BT4 × BT4P, BT5 × BT4, BT6 × SGP and SGP × BT6. Keywords: hybrid, performance, total soluble solids, watermelon   ABSTRAK Pemuliaan hibrida pada semangka mengarah kepada pembentukan varietas berdaya hasil tinggi. Penelitian bertujuan untuk mengetahui keragaan hibrida semangka koleksi Balitbu Tropika dan untuk mengevaluasi keunggulan masing-masing hibrida Penelitian dilaksanakan di Kebun Percobaan Sumani, Balitbu Tropika, Solok, Sumatera Barat, dari bulan April sampai dengan Juli 2016. Materi yang digunakan terdiri dari 19 kombinasi persilangan. Data hasil penelitian deskriptif ini ditampilkan dalam bentuk rataan dan gambar. Hasil penelitian menunjukkan bahwa hibrida yang diuji memiliki keragaman dalam ukuran, warna kulit buah, warna daging buah, ketebalan kulit buah dan kemanisan. Belum ditemukan hibrida yang memiliki tiga karakter unggul, yang terdiri dari bobot buah sedang, total padatan terlarut (total soluble solid) tinggi, dan kulit buah agak tebal. Hibrida yang memiliki keunggulan berupa rasa manis dan tahan simpan adalah BT1 × SGP, BT4 × BT4P, BT5 × BT4, BT6 × SGP dan SGP × BT6. Kata kunci: hibrida, keragaan, semangka, total padatan terlarut


Processes ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 3
Author(s):  
Norazlin Abdullah ◽  
Nyuk Ling Chin

Extraction of tropical fruit juice using simple, efficient, and environmentally friendly technologies is gaining importance to produce high quality juices. Juice from pink-fleshed guava, pink-fleshed pomelo, and soursop was extracted using direct and indirect thermosonication methods by varying intensity, time, and temperature, and compared to those extracted using water bath incubation. Improvised models of juice yield, ascorbic acid, and total soluble solids responses were generated by eliminating insignificant model terms of the factors in full quadratic model using backward eliminating procedure. Main effects, 3D, or 4D plots for each response were developed based on factors that influenced the response. Results showed that the best extraction method for guava and pomelo juices were within indirect thermosonication method of 1 kW, 55 °C and 30 min, and 2.5 kW, 54 °C and 23 min, respectively. Direct thermosonication method at 10% amplitude, 55 °C for 2 to 10 min was more suitable for soursop juice. Thermosonicated extraction of tropical fruit juice can improve its juice yield, ascorbic acid content, and total soluble solids content.


Antioxidants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 820
Author(s):  
José M. Lorente-Mento ◽  
Fabián Guillén ◽  
Salvador Castillo ◽  
Domingo Martínez-Romero ◽  
Juan M. Valverde ◽  
...  

The effect of melatonin pomegranate tree treatments on fruit quality and bioactive compounds with antioxidant activity at harvest and during storage at 10 °C for 60 days was assayed in two consecutive years, 2019 and 2020. In the first year, trees were treated with 0.1, 0.3 and 0.5 mM of melatonin along the developmental fruit growth cycle, and results showed that bioactive compounds (total phenolics and total and individual anthocyanins) and antioxidant activity at harvest were higher in fruits from melatonin-treated trees than in controls. Other fruit quality parameters, such as firmness, total soluble solids and aril red colour, were also increased as a consequence of melatonin treatment. In fruit from control tress, firmness and acidity levels decreased during storage, while increases occurred on total soluble solids, leading to fruit quality reductions. These changes were delayed, and even maintenance of total acidity was observed, in fruit from melatonin-treated trees with respect to controls, resulting in a fruit shelf-life increase. Moreover, concentration of phenolics and anthocyanins and antioxidant activity were maintained at higher levels in treated than in control fruits during the whole storage period. In general, all the mentioned effects were found at the highest level with the 0.1 mM melatonin dose, and then it was selected for repeating the experiment in the second year and results of the first year were confirmed. Thus, 0.1 mM melatonin treatment could be a useful tool to enhance aril content on bioactive compounds with antioxidant activity and health beneficial effects and to improve quality traits of pomegranate fruit, at harvest and during postharvest storage.


Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 803
Author(s):  
Elia Nora Aquino-Bolaños ◽  
Alma Karina Garzón-García ◽  
Jimena Esther Alba-Jiménez ◽  
José Luis Chávez-Servia ◽  
Araceli Minerva Vera-Guzmán ◽  
...  

The green bean is an important crop worldwide, because it is rich in protein, dietary fiber, vitamins, and minerals, as well as bioactive compounds that provide it with important functional properties; however, the composition of many landraces is still unknown. The purpose of this project was to characterize Phaselus vulgaris and coccineus L. landrace green beans on pH, titratable acidity, total soluble solids, total sugars, color parameters, total phenols, monomeric anthocyanins, and in vitro antioxidant activity (DPPH and FRAP). Regarding the content of total sugars, differences were registered between both species, as opposed to results observed in total soluble solids. Color parameters showed higher reddish tones for P. vulgaris landraces, though P. coccineus had a higher total phenolic content, especially the reddish landraces, which correlated directly to a higher antioxidant activity by DPPH and FRAP. In the protein content, the species P. vulgaris registered the highest content. These results could contribute to a greater use and even promote the genetic improvement of the outstanding pods that serve as one of the main food products in rural regions for higher benefits.


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