Effect of spray drying on bioactive and volatile compounds in soursop (Annona muricata) fruit pulp

Soursop (Annona muricata) Properties and Perspectives for Integral Valorization

The increased international interest in the properties of soursop (Annona muricata) alerts us to the sustainability of productive chain by-products, which are rich in phytochemicals and other properties justifying their industrial application in addition to reducing the environmental impact and generating income. Chemical characteristics of soursop by-products are widely known in the scientific community; this fruit has several therapeutic effects, especially its leaves, enabling it to be used by the pharmaceutical industry. Damaged and non-standard fruits (due to falling and crushing) (30-50%), seeds (3-8.5%), peels (7-20%), and leaves, although they constitute discarded waste, can be considered as by-products. There are other less cited parts of the plant that also have phytochemical components, such as the columella and the epidermis of the stem and root. Tropical countries are examples of producers where soursop is marketed as fresh fruit or frozen pulp, and the valorization of all parts of the fruit could represent important environmental and economic perspectives. Based on the chemical composition of the fruit as well as its by-products and leaves, this work discusses proposals for the valorization of these materials. Soursop powder, bioactive compounds, oil, biochar, biodiesel, bio-oil, and other products based on published studies are presented in this work, offering new ideas for opportunities for the regions and consumers that produce soursop.

Flavour chemistry of dehydrated exotic fruits

Dehydrated fruit pieces and purées are commonly used in many food formulations and toppings for food products like yogurts, ice creams, and cereals. However, one of the biggest problems in fruit dehydration is the prevention of the development of unpleasant off-flavour that can negatively impact on the sensory quality of the final dried fruit products. In recent years, fruit dehydration has been conducted using either thermal or non-thermal drying techniques. Therefore, the present review examines how the different dehydration technologies, namely conventional hot air-drying, ultrasonic-assisted hot air-drying, sun-drying, spray-drying, Refractance WindowTM drying, cast-tape drying, thin-layer catalytic far-infrared radiation drying, withering, freeze-drying, microwave-drying, and osmotic dehydration impact on the volatile constituents of the final dried fruit products. Drying processes result in noticeable losses/reduction of several impact odorants. Moreover, some compounds are produced either via: (1) hydrolysis of relevant glycosides under high temperatures, or (2) thermal degradation of volatile and non-volatile precursors as well as oxidation and Maillard reactions which result in the production of heterocyclics, and saturated and unsaturated aldehydes. Of significance is the Refractance WindowTM drying which exhibits high retention potential (~ 90%) of volatile compounds present in fresh fruits. Refractance WindowTM drying technology ensures rapid drying of food products at very low temperature.

Nutritional and Therapeutic Potential of Soursop

Soursop (Annona muricata) has been one of the most studied fruits in recent years, owing to its potential medicinal benefits, as evidenced by many studies. Soursop is a tropical and subtropical fruit having great versatility and is quite sensitive to drastic temperature fluctuations. Since soursop contains various phytochemicals, it can be used medicinally to treat a wide range of conditions, including diabetes (by inhibiting the enzymes α-glucosidase and α-amylase), tumor, cancer, oxidative stress, blood pressure, the induction of apoptosis in tumor cells as well as hemorrhagic disease and cholesterol lowering. Due to its significant nutritional profile and therapeutic potential, it can be utilized in the development of nutraceuticals and medicines. Its pulp, seed, and leaf extract are used as functional ingredients in different foods as value-added foods. This review article is intended to characterize fruit development patterns and examines potential maturity indicators in soursop. In addition, it also elaborates on the potential nutritional and active phytochemicals present in this magnificent gift of nature and their possible uses in the food and pharmaceutical industries.

Branched-Chain Volatiles in Fruit: A Molecular Perspective

Branched-chain volatiles (BCVs) constitute an important family of fruit volatile metabolites essential to the characteristic flavor and aroma profiles of many edible fruits. Yet in contrast to other groups of volatile organic compounds important to fruit flavor such as terpenoids, phenylpropanoids, and oxylipins, the molecular biology underlying BCV biosynthesis remains poorly understood. This lack of knowledge is a barrier to efforts aimed at obtaining a more comprehensive understanding of fruit flavor and aroma and the biology underlying these complex phenomena. In this review, we discuss the current state of knowledge regarding fruit BCV biosynthesis from the perspective of molecular biology. We survey the diversity of BCV compounds identified in edible fruits as well as explore various hypotheses concerning their biosynthesis. Insights from branched-chain precursor compound metabolism obtained from non-plant organisms and how they may apply to fruit BCV production are also considered, along with potential avenues for future research that might clarify unresolved questions regarding BCV metabolism in fruits.

Comparative evaluation of chemical composition and biological activities of tropical fruits consumed in Manaus, central Amazonia, Brazil

Fruits are widely recognized as sources of biologically active metabolites, such as antioxidant compounds. In this context, fruits commonly consumed in the central Amazonia, especially in its biggest metropolis (Manaus - AM/Brazil), are attractive as potential sources of antioxidant compounds related to biological activities. Most of such fruits are still poorly studied and/or remain unknown outside the Amazon region. Therefore, this study aims to investigate nine fruits (abiu, cubiu, biribá, breadfruit, genipap, peach palm, murici, soursop, and umari) regarding their chemical composition (fixed and volatile), reducing capacity, antioxidant activity, enzyme inhibition, and cytotoxicity. Determination of small organic acids, hydroxycinnamic acids, flavan-3-ols and flavonoid aglycones was done by HPLC-MS/MS, whereas determination of volatile organic compounds (VOCs) was done by HS-SPME/GC-MS. Reducing capacity was determined by the Folin-Ciocalteu method, and antioxidant activities were evaluated by DPPH, ABTS, and H-ORAC_FL assays. In vitro activities regarding inhibition of enzymes were tested for α-glucosidase, lipase, and α-amylase, and anti-glycation activities were evaluated for methylglyoxal and fructose. Cytotoxicity of fruit extracts was evaluated by cell viability of human fibroblast cell line (MRC-5). A total of 16 antioxidant compounds and 139 VOCs were determined, whose profiles were unique for each studied fruit. Total phenolic contents as well as antioxidant activities found herein were similar or even higher than those reported for several traditional fruits. Some of fruit extracts were able to inhibit α-glucosidase and glycation in methylglyoxal and fructose models, whereas none of them was active for lipase and α-amylase. All of the fruit extracts showed to be non-cytotoxic to MRC-5 cell line.

Valorization of byproducts from tropical fruits: Extraction methodologies, applications, environmental, and economic assessment: A review (Part 1: General overview of the byproducts, traditional biorefinery practices, and possible applications)

Tropical fruits represent one of the most important crops in the world. The continuously growing global market for the main tropical fruits is currently estimated at 84 million tons, of which approximately half is lost or wasted throughout the whole processing chain. Developing novel processes for the conversion of these byproducts into value-added products could provide a viable way to manage this waste problem, aiming at the same time to create a sustainable economic growth within a bio-economy perspective. Given the ever-increasing concern about sustainability, complete valorization through a bio-refinery approach, that is, zero waste concept, as well as the use of green techniques is therefore of utmost importance. This paper aims to report the status on the valorization of tropical fruit byproducts within a bio-refinery frame, via the application of traditional methodologies, and with specific attention to the extraction of phenolics and carotenoids as bioactive compounds. The different types of byproducts, and their content of bioactives is reviewed, with a special emphasis on the lesser-known tropical fruits. Moreover, the bioactivity of the different types of extracts and their possible application as a resource for different sectors (food, pharmaceutical, and environmental sciences) is discussed. Consequently, this review presents the concepts of tropical fruit biorefineries, and the potential applications of the isolated fractions.