Characterisation and stability of quality indices on storage of pumpkin (Cucurbita moschata and Cucurbita maxima) purees

A quantitative and qualitative investigation of the impact of irradiation on the physico-chemical of pointed gourd during storage

Irradiation effect on the physico-chemical characteristics and shelf stability of pointed gourd was investigated in research. It was estimated that moisture content, total phenol and total carotenoids was significantly (p≤0.05) decreased while physiological loss in weight, total soluble solids, lutein and α-cryptoxanthin were increased during the completion of study. The three carotenoid pigments (β-carotene, lutein, α-cryptoxanthin) were identified by Thin Layer Chromatography (TLC) and spectrophotometric method and its changes reported during storage in control and irradiated sample. The principal component analysis showed that b* value, Physiological Loss Weight (PLW), adhesiveness and acidity have negative correlation with rest of the parameters during storage. The research will present a progressive strategy for increasing the storage stability of pointed gourd during transportation and storage in India's government and private mandis.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-022-05395-3.

Effect of Processing on Color, Rheology and Bioactive Compounds of Different Sweet Pepper Purees

Sweet pepper purees (red, yellow and green) were examined for FTIR (Fourier-transform infrared spectroscopy), chemical, bioactive, color and rheological parameters. FTIR technique was used to evaluate the functional groups. FTIR wave numbers are associated with the absorption bands that depicted the presence of several phytocompounds in the purees. Among the chemical parameters, water activity varied non-significantly whereas, total soluble sugars (TSS), sugars and pH increased after processing of the fruits into purees. The presence of bioactive compounds depends on the variety of sweet pepper. The red puree had significantly higher carotenoids, phenolics and antioxidant capacity followed by yellow and green pepper purees. The minimal change was observed in the color of purees during processing. The purees were subjected to different shear rate (1 to 50 s^-1) to evaluate the effect on viscosity and shear stress that is desirable for its end use in different food products. All purees show the shear thinning behavior as shear rate increased. Results revealed that heat processing of sweet peppers didn't affect color, sugars, carotenoids, phenolics and antioxidant capacity to a greater extent. The finding will be helpful to manage seasonal bulk production efficiently and make them available as an ingredient in various food products.

Metabolic and transcriptomic analysis of two Cucurbita moschata germplasms throughout fruit development

BACKGROUND

Pumpkins (Cucurbita moschata; Cucurbitaceae) are valued for their fruits and seeds and are rich in nutrients. Carotenoids and sugar contents, as main feature of pumpkin pulp, are used to determine the fruit quality.

RESULTS

Two pumpkin germplasms, CMO-X and CMO-E, were analyzed regarding the essential quality traits such as dry weight, soluble solids, organic acids, carotenoids and sugar contents. For the comparison of fruit development in these two germplasms, fruit transcriptome was analyzed at 5 different developmental stages from 0 d to 40 d in a time course manner. Putative pathways for carotenoids biosynthesis and sucrose metabolism were developed in C. moschata fruit and homologs were identified for each key gene involved in the pathways. Gene expression data was found consistent with the accumulation of metabolites across developmental stages and also between two germplasms. PSY, PDS, ZEP, CRTISO and SUS, SPS, HK, FK were found highly correlated with the accumulation of carotenoids and sucrose metabolites, respectively, at different growth stages of C. moschata as shown by whole transcriptomic analysis. The results of qRT-PCR analysis further confirmed the association of these genes.

CONCLUSION

Developmental regulation of the genes associated with the metabolite accumulation can be considered as an important factor for the determination of C. moschata fruit quality. This research will facilitate the investigation of metabolic profiles in other cultivars.

Nutritional and sensory evaluation of pumpkin-based (Cucurbita maxima) functional juice

Purpose

Pumpkins are a rich source of essential nutrients, namely, β-carotene, minerals and vitamins, and they are therefore suitable for making functional juice. This study aims to develop pumpkin-based functional juice and assess the acceptability of the product by various consumers. In total, 55 per cent of the panelists disliked the pumpkin juice because of its strong off-flavor. Consequently, different blends of pumpkin juice with mango, orange, strawberry and green apple juices were prepared and evaluated for global appreciation and descriptive sensory analysis.

Methodology

Pumpkins, green apples, mangos, oranges and strawberries were obtained from the local market. Four mixtures of juices were prepared by mixing pumpkin and mango juice (750/250, v/v), pumpkin and green apple juice (750/250, v/v), pumpkin and orange juice (750/250, v/v) and pumpkin with strawberry and orange juice (750/125/125, v/v/v). The contents of moisture ash, fiber, carbohydrate, crude protein and lipids were estimated according to AOAC methods. β-Carotene, vitamin C and minerals were determined. A semi-trained panel consisting of 100 members assessed sensory characteristics of pumpkin juice and mixtures using a quantitative descriptive analysis method (QDA) for different attributes.

Findings

The findings show that the moisture, crude protein, fiber, ash and carbohydrate contents indicate that the developed pumpkin juice was rich in these essential nutrients. The fiber value in our study was lower than the value previously reported for pumpkin. The content of β-carotene and vitamin C in the developed pumpkin juice was considerably higher than that reported previously for fruits. The values of calcium and iron of the current study were much higher than those previously reported in vegetable juices and mixtures. The sensory results revealed that the developed pumpkin-based juice blends are acceptable by the consumers.

Originality value

This study was carried out to develop a suitable formula for preparing functional juices from pumpkin, which is not consumed willingly by children and the elderly; the authors aimed to improve its taste and flavor by mixing it with different fruit juices. The results demonstrated that pumpkin juice is rich in essential nutrients such as vitamins, minerals and antioxidants, suggesting its health-promoting potential. Mixing pumpkin juice with mango juice or orange and strawberry juices significantly improved the sensory quality of the products. Strikingly, the formulated pumpkin juice mixtures received good acceptance and appreciation by children and the elderly, which could promote its use as a functional juice. Generally, pumpkin-based juice blends are rich in vitamins, minerals and antioxidants and can therefore be consumed as a functional beverage with potentially increased health-promoting characteristics. Using pumpkin for developing functional juices could add commercial value to pumpkins. Future studies should specifically focus on large-scale production and commercialization of these juice mixtures.

Impact of electron beam irradiation on quality of sea buckthorn (Hippophae rhamnoides L.) oil

BACKGROUND

Sea buckthorn oil is a valuable product that can be incorporated into daily foodstuffs, cosmetics or pharmaceuticals. The effect of accelerated electron irradiation up to 8 kGy on quality characteristics of sea buckthorn oil was investigated in this study.

RESULTS

Irradiation had no significant influence on phenolic content. Conversely, carotenoid content, antioxidant activity, and oxidative status suffered alterations as the irradiation dose increased. Although no colour changes were visible for oil irradiated up to 3 kGy, the total colour difference indicated clearly changes that involved a two-step pattern associated with slow degradation of oil colour up to 3 kGy, followed by a fast degradation up to 8 kGy. Some changes of the oil spectral features related to the frequency and intensity of some bands have been found after irradiation, indicating an alteration of the structural integrity induced by irradiation.

CONCLUSION

The present investigation may be a useful starting point for irradiation processing of food or non-food matrices containing sea buckthorn oil. Thus, sea buckthorn oil safety can be ensured with minimal undesirable changes in its quality by applying irradiation doses up to 3 kGy, which allow control of the microbial contamination depending on microorganism type and initial microbial load.

Impact of high pressure processing on color, bioactive compounds, polyphenol oxidase activity, and microbiological attributes of pumpkin purée

Physicochemical parameters, bioactive compounds' content (carotenoids and total phenols), total antioxidant activity, and enzymatic activity of polyphenol oxidase (PPO) were evaluated after high pressure processing (HPP) on a pumpkin purée (cv. 'Butternut'). Three pressure levels (400, 500, and 600 MPa) were combined with three holding times (200, 400, and 600 s). The applied treatments reduced the levels of total aerobic mesophilic (TAM), total psychrophilic and psychrotrophic bacteria (TPP), and molds and yeasts (M&Y). All applied treatments did not affect enzymatic activity of PPO. Pressure level increased CIE L* values, which could enhance the lightness perception of high pressure (HP)-treated purées. No differences were found between the untreated and HP-treated purées regarding total phenols and carotenoids content (lutein, α-carotene, and β-carotene) and total antioxidant activity. HPP did not affect most quality parameters and maintained the levels of bioactive compounds. However, it did not achieve the complete inhibition of PPO, which could reduce the shelf-life of the pumpkin purée.