Effect of Thermal and Alternate Thermal Processing on Bottle Gourd (L agenaria siceraria ) Juice

Safety and antidiabetic activity of Lagenaria siceraria (Molina) Standl. juice in streptozotocin -induced diabetic rats

ETHNOPHARMACOLOGICAL RELEVANCE

Diabetes and its complications have overwhelmed India's healthcare system. Current therapies are expensive and have adverse side effects, thus dietary changes and alternative treatments are needed. Lagenaria siceraria (Molina) Standl. Juice is used mainly for its nutritional and medicinal values, however toxicity of the juice and antidiabetic effects have been poorly characterized.

AIM OF THE STUDY

To investigate the toxicity, anti-diabetic and anti-inflammatory efficacy of Lagenaria siceraria (Molina) Standl. (LS) juice.

MATERIALS AND METHODS

In vitro antidiabetic (α-glucosidase, α-amylase and DPP-4 inhibitory) activities were screened using standard procedures. The glucose uptake test was carried out by using L6 rat skeletal muscle cell line. In vivo sub-acute toxicity of LS juice was assessed on Wistar rats. Wistar rats were induced with diabetes by a single intraperitoneal (I.P) injection of freshly prepared streptozotocin (55 mg/kg body weight). The animals were randomly divided into 6 groups: normal control, untreated diabetic control, diabetic rats. Different dose of 200 mg/kg, 400 mg/kg and 600 mg/kg body weight of LS juice were administered, one group of diabetic rats were administered with 2 IU/mL insulin. The rats were sacrificed on the 31st day of the experiment and various in vivo biochemical parameters were evaluated in the serum and tissue homogenates of diabetic rats.

RESULTS

Significant dose-dependent inhibition of α-amylase (22.6%), α-glucosidase (50.13%), and DPP-4 (61.50%) activity was observed by LS juice. LS juice (10 μg/mL) increased insulin-mediated 2NBDG (2-(N-(7-Nitrobenz-2-oxa-1,3-diazol-4-yl) Amino)-2-Deoxyglucose) absorption in L6 cells. Animals treated with LS juice showed no toxicity or unfavorable pharmacological effects. Lagenaria siceraria (Molina) Standl. Juice improved glucose tolerance in diabetic rats with reduced fasting blood glucose. Lipopolysaccharide induced NF-κB, TNF-α and IL-1β production was also decreased in rats fed with LS juice.

CONCLUSION

Lagenaria siceraria (Molina) Standl. Juice has demonstrated promising anti-inflammatory properties as well as the capacity to inhibit the digestion enzymes glucosidase and amylase. Our findings thus open new avenues for further research into the antidiabetic potential of LS juice.

Underutilized green leafy vegetables: frontier in fortified food development and nutrition

From the ancient period, Green leafy vegetables (GLV) are part of the daily diet and were believed to have several health beneficial properties. Later it has been proved that GLV has outstanding nutritional value and can be used for medicinal benefits. GLV is particularly rich in minerals like iron, calcium, and zinc. These are also rich in vitamins like beta carotene, vitamin E, K, B and vitamin C. In addition, some anti-nutritional elements in GLV can be reduced if it is grown properly and processed properly before consumption. Tropical countries have a wide variety of these green plants such as Red Spinach, Amaranth, Malabar Spinach, Taro Leaf, Fenugreek leaf, Bengal Gram Leaves, Radish Leaves, Mustard Leaves, and many more. This review focuses on listing this wide range of GLVs (in total 54 underutilized GLVs) and their compositions in a comparative manner. GLV also possesses medicinal activities due to its rich bioactive and nutritional potential. Different processing techniques may alter the nutritional and bioactive potential of the GLVs significantly. The GLVs have been considered a food fortification agent, though not explored widely. All of these findings suggest that increasing GLV consumption could provide nutritional requirements necessary for proper growth as well as adequate protection against diseases caused by malnutrition.

Sensory evaluation of microwave-ultrasound treated bottle gourd juice using hybrid features of fuzzy logic and proportional odd modelling approach

In the present investigation, sensory evaluation of bottle gourd juice (BGJ) samples, obtained from microwave-ultrasound based combined treatment was performed. The raw (sample-1) and conventionally treated (sample-2) alongside microwave-ultrasound treated (sample-3) were considered for the assessment of sensory evaluation. An innovative approach of hybrid fuzzy logic and proportional odd modelling (FL-POM) was implemented for the analysis of the sensory scores. The similarity values for the juice samples and their quality attributes were resolved from the results obtained by fuzzy logic. These values were considered as input for hybridization with the POM approach. The assessed coefficients obtained from the results of POM were considered for the ranking of the samples and quality traits. The ranking of the BGJ samples was observed in the order of sample-1 > sample-3 > sample-2, and their related quality attributes ranked in the order color > taste > aroma > mouth feel. The microwave-ultrasound treated BGJ evinced as the best sample in comparison to the raw one.

How to comprehensively improve juice quality: a review of the impacts of sterilization technology on the overall quality of fruit and vegetable juices in 2010-2021, an updated overview and current issues

Fruit and vegetable juices (FVJ) are rich in nutrients, so they easily breed bacteria, which cause microbial pollution and rapid deterioration of their quality and safety. Sterilization is an important operation in FVJ processing. However, regardless of whether thermal sterilization or non-thermal sterilization is used, the effect and its impact on the overall quality of FVJ are strongly dependent on the processing parameters, microbial species, and FVJ matrix. Therefore, for different types of FVJ, an understanding of the impacts that different sterilization technologies have on the overall quality of the juice is important in designing and optimizing technical parameters to produce value-added products. This article provides an overview of the application of thermal and non-thermal technique in the field of FVJ processing over the past 10 years. The operating principle and effects of various technologies on the inactivation of microorganisms and enzymes, nutritional and functional characteristics, physicochemical properties, and sensory quality of a wide range of FVJ are comprehensively discussed. The application of different combinations of hurdle technology in the field of FVJ sterilization processing are also discussed in detail. Additionally, the advantages, limitations, and current application prospects of different sterilization technologies are summarized.

Ohmic Heating Extraction at Different Times, Temperatures, Voltages, and Frequencies: A New Energy-Saving Technique for Pineapple Core Valorization

Pineapple core is considered a processing by-product. This study proposed and evaluated an ohmic heating extraction-based valorization platform to obtain value-added bioactive compounds from pineapple core and studied the effects of four important processing parameters. In this sense, a Taguchi design (L16(4)4) was used to assess the effects of temperature (70, 80, 90, and 100 °C), time (15, 30, 45, and 60 min), voltage (110, 160, 210, and 260 V), and frequency (60, 340, 620, and 900 Hz) on heating rate, come-up time, energy consumption, system performance efficiency, total phenolic compounds (TPC), DPPH, and ABTS. Finally, a side-by-side comparison of optimized ohmic heating (OOH) and conventional extraction was performed, and chemical composition was compared by ultra-performance liquid chromatography equipped with photodiode array detection-mass (UPLC-DAD-ESI-MS-MS). According to the results, increasing temperatures enhanced system performance efficiency but negatively affected TPC and antioxidant values above 90 ℃. Similarly, prolonging the extraction (>30 min) decreased TPC. Further, increasing voltage (from 110 to 260 V) shortened the come-up time (from 35.75 to 5.16 min) and increased the heating rate (from 2.71 to 18.80 °C/min−1). The optimal conditions were 30 min of extraction at 80 °C, 160 V, and 900 Hz. Verification of the optimal conditions revealed that OOH yielded an extract with valuable bioactive compounds and saved 50% of the time and 80% of energy compared to the conventional treatment. The UPLC-DAD-ESI-MS-MS showed that there were similarities between the chemical profiles of the extracts obtained by conventional and OOH methods, while the concentration of major compounds varied depending on the extraction method. This information can help achieve sustainable development goals (SDGs) by maximizing the yield and minimizing energy and time consumption.

Effect of CO2 Preservation Treatments on the Sensory Quality of Pomegranate Juice

Due to the interest in identifying cost-effective techniques that can guarantee the microbiological, nutritional, and sensorial aspects of food products, this study investigates the effect of CO2 preservation treatment on the sensory quality of pomegranate juice at t0 and after a conservation period of four weeks at 4 °C (t28). The same initial batch of freshly squeezed non-treated (NT) juice was subjected to non-thermal preservation treatments with supercritical carbon dioxide (CO2), and with a combination of supercritical carbon dioxide and ultrasound (CO2-US). As control samples, two other juices were produced from the same NT batch: A juice stabilized with high pressure treatment (HPP) and a juice pasteurized at high temperature (HT), which represent an already established non-thermal preservation technique and the conventional thermal treatment. Projective mapping and check-all-that-apply methodologies were performed to determine the sensory qualitative differences between the juices. The volatile profile of the juices was characterized by gas chromatography-mass spectrometry. The results showed that juices treated with supercritical CO2 could be differentiated from NT, mainly by the perceived odor and volatile compound concentration, with a depletion of alcohols, esters, ketones, and terpenes and an increase in aldehydes. For example, in relation to the NT juice, limonene decreased by 95% and 90%, 1-hexanol decreased by 9% and 17%, and camphene decreased by 94% and 85% in the CO2 and CO2-US treated juices, respectively. Regarding perceived flavor, the CO2-treated juice was not clearly differentiated from NT. Changes in the volatile profile induced by storage at 4 °C led to perceivable differences in the odor quality of all juices, especially the juice treated with CO2-US, which underwent a significant depletion of all major volatile compounds during storage. The results suggest that the supercritical CO2 process conditions need to be optimized to minimize impacts on sensory quality and the volatile profile.

Lactic Fermented Fruit or Vegetable Juices: Past, Present and Future

Numerous traditional low-alcohol fermented beverages produced from fruit or vegetables are described around the world. Fruit and vegetables and lactic fermented products both present nutritional benefits, which give reasons for the recent expansion of non-dairy lactic fermented juices on the market. In addition, fruit and vegetable juices are new carriers for probiotic bacteria. Specific phenotypic traits of lactic acid bacteria (LAB) are required so that LAB can effectively grow in fruit or vegetable juices, increase their safety and improve their sensory and nutritional quality. From the diversity of microbiota of spontaneous fermentations, autochthonous starters can be selected, and their higher performance than allochthonous LAB was demonstrated. Achieving long-term storage and constant high quality of these beverages requires additional processing steps, such as heat treatment. Alternatives to conventional treatments are investigated as they can better preserve nutritional properties, extract bioactive compounds and promote the growth and metabolism of LAB. Specific processing approaches were shown to increase probiotic viability of fruit and vegetable juices. More knowledge on the metabolic activity of lactic acid bacterium consortium in fruit or vegetable juices has become a bottleneck for the understanding and the prediction of changes in bioactive compounds for functional beverages development. Hopefully, the recent developments of metabolomics and methods to describe enzymatic machinery can result in the reconstruction of fermentative pathways.

Application of microwave and ohmic heating for pasteurization of cantaloupe juice: microbial inactivation and chemical properties

BACKGROUND

Cantaloupe melon (Cucumis melo L.) is one of the most important dessert fruits and is cultivated in many countries of the world. The effects of microwave (400 and 800 W for 110 s), ohmic (100 and 200 V for 110 s) and conventional heating (27-75 °C for 30 min) treatments on inactivation of Escherichia coli, Salmonella Typhimurium, S. Enteritidis and Staphylococcus aureus pathogens; pH and degradation of vitamin C, β-carotene and phenolic compounds of cantaloupe juice were investigated.

RESULTS

As time passed, all of the treatments resulted in significant (P ≤ 0.05) decreases in the number of pathogens and vitamin C, β-carotene and phenolic compound content, whereas the pH of samples did not show significant changes. The mentioned parameters were more reduced by increasing the power, voltage and temperature of ohmic, microwave and conventional heating treatments, respectively. Comparison of the results for conventional heating with those of ohmic and microwave heating revealed that the complete inactivation time of pathogens by the two latter treatments was much shorter than that of the former. After 20 s, the effect of ohmic heating at 200 V on decreasing vitamin C content was significantly (P ≤ 0.05) higher than that of the other treatments. The amounts of β-carotene and phenolic compounds showed the most reduction under 800 W microwave treatment.

CONCLUSION

The results obtained for conventional, ohmic and microwave heating treatments indicated a higher degradation of β-carotene and phenolic compounds and a lower loss of vitamin C in the former. © 2019 Society of Chemical Industry.

Changes in total phenolic content and color of bottle gourd (Lagenaria siceraria) juice upon conventional and ohmic blanching

Plant phenolics exist in a complex matrix and require a high separation capacity for analysis. Bottle gourd (BG) was blanched using conventional thermal and alternate thermal ohmic heating methods using different combinations of temperature (60-90°C) and time (1-5min), and the effect of these methods on total phenolic content (TPC) and color was examined. Complete characterization on the basis of the phenolic profile of unblanched, ohmically blanched, and conventionally blanched samples of BG was studied. Gas chromatography-mass spectrometry and Liquid chromatography-mass spectrometry were used to detect volatile and nonvolatile phenolic compounds, respectively. The color profiles of the unblanched and conventionally and ohmically blanched samples were studied via hunterLab colorimeter using L*, a*, and b* coordinates. The highest increase in TPC was observed at 80°C, 4 min and 90°C, 5min in the case of ohmic and conventional blanching, respectively. The conventionally and ohmically blanched samples both produced desirable green-color retention in comparison to the unblanched samples; however, highest retention was observed in the ohmically blanched samples. The ohmically blanched samples exhibited the maximum extraction of phenolic compounds and better color of BG juice in comparison to the other samples.