Does an apple a day keep away diseases? Evidence and mechanism of action

Apples and their products exemplify the recently reemphasized link between dietary fruit intake and the alleviation of human disease. Their consumption does indeed improve human health due to their high phytochemical content. To identify potentially relevant articles from clinical trials, some epidemiological studies and meta-analyses, and in vitro and in vivo studies (cell cultures and animal models), PubMed was searched from January 1, 2012, to May 15, 2022. This review summarized the potential effects of apple and apple products (juices, puree, pomace, dried apples, extracts rich in apple bioactives and single apple bioactives) on health. Apples and apple products have protective effects against cardiovascular diseases, cancer, as well as mild cognitive impairment and promote hair growth, healing of burn wounds, improve the oral environment, prevent niacin-induced skin flushing, promote the relief of UV-induced skin pigmentation, and improve the symptoms of atopic dermatitis as well as cedar hay fever among others. These effects are associated with various mechanisms, such as vascular endothelial protection, blood lipids lowering, anti-inflammatory, antioxidant, antiapoptotic, anti-invasion, and antimetastatic effects. Meanwhile, it has provided an important reference for the application and development of medicine, nutrition, and other fields.

Health Benefits of Apple Juice Consumption: A Review of Interventional Trials on Humans

Although numerous studies have reported the benefits of apple consumption on cardiometabolic health parameters and chronic disease prevention, few have focused on the effects of apple juice specifically. Juice consumption may be a convenient way to take advantage of the health effects of the bioactive components present in apples. The present review aims to summarize the current literature on health benefits of apple juice as reported in clinical trials in humans. Of the 67 studies retained, 20 interventional studies on humans were reviewed. Overall, cloudy apple juice consumption was found to be associated with several markers of cardiovascular health that may ultimately be relevant for cancer and neurodegenerative diseases. Most of the documentation was found regarding oxidative stress, as well as observations with other parameters such as markers of inflammation, lipid profile, and diabetes. This review suggests that, in 20 studies, apple juice consumed in moderation exerts positive effects on markers of cardiovascular disease risk (particularly on oxidative stress).

Effects of Thermal and High-Pressure Processing on Quality Features and the Volatile Profiles of Cloudy Juices Obtained from Golden Delicious, Pinova, and Red Delicious Apple Cultivars

In this study, juices extracted from three apple cultivars (Golden Delicious, Pinova, and Red Delicious) were stabilized by means of thermal treatment (TT) and high-pressure processing (HPP, 600 MPa 3 min); pH, total titratable acidity, total soluble solids content, color, and viscosity, as well as volatile profile, were investigated. Qualitative characteristics (pH, titratable acidity, colorimetric parameters, viscosity, and volatile profile) results were significantly influenced by both cultivars and treatments; for example, juice viscosity greatly increased after HPP treatment for Golden Delicious, and after both TT and HPP for Pinova, while no influence of stabilization treatment was registered for Red Delicious juices. Regarding the volatile profile, for Golden Delicious cultivar, HPP treatment determined an increase in volatile compounds for most of the classes considered, leading to a supposed quality implementation. For the other two cultivars, the stabilization treatment that better preserved the volatile profile was the HPP one, even if the results were quite similar to the thermal treatment. Further studies are needed to evaluate different time/pressure combinations that could give better results, depending on the specific apple cultivar.

An Overview of the Factors Influencing Apple Cider Sensory and Microbial Quality from Raw Materials to Emerging Processing Technologies

Given apple, an easily adapted culture, and a large number of apple varieties, the production of apple cider is widespread globally. Through the fermentation process, a series of chemical changes take place depending on the apple juice composition, type of microorganism involved and technology applied. Following both fermentations, alcoholic and malo-lactic, and during maturation, the sensory profile of cider changes. This review summarises the current knowledge about the influence of apple variety and microorganisms involved in cider fermentation on the sensory and volatile profiles of cider. Implications of both Saccharomyces, non-Saccharomyces yeast and lactic acid bacteria, respectively, are discussed. Also are presented the emerging technologies applied to cider processing (pulsed electric field, microwave extraction, enzymatic, ultraviolet and ultrasound treatments, high-pressure and pulsed light processing) and the latest trends for a balanced production in terms of sustainability, authenticity and consumer preferences.

Variations in Triterpenoid Deposition in Cuticular Waxes during Development and Maturation of Selected Fruits of Rosaceae Family

The process of fruit ripening involves many chemical changes occurring not only in the mesocarp but also in the epicarp, including changes in the triterpenoid content of fruit cuticular waxes that can modify the susceptibility to pathogens and mechanical properties of the fruit surface. The aim of the study was the determination of the ripening-related changes in the triterpenoid content of fruit cuticular waxes of three plant species from the Rosaceae family, including rugosa rose (Rosa rugosa), black chokeberry (Aronia melanocarpa var. “Galicjanka”) and apple (Malus domestica var. “Antonovka”). The triterpenoid and steroid content in chloroform-soluble cuticular waxes was determined by a GC-MS/FID method at four different phenological stages. The profile of identified compounds was rather similar in selected fruit samples with triterpenoids with ursane-, oleanane- and lupane-type carbon skeletons, prevalence of ursolic acid and the composition of steroids. Increasing accumulation of triterpenoids and steroids, as well as the progressive enrichment of the composition of these compounds in cuticular wax during fruit development, was observed. The changes in triterpenoid content resulted from modifications of metabolic pathways, particularly hydroxylation and esterification, that can alter interactions with complementary functional groups of aliphatic constituents and lead to important changes in fruit surface quality.

Fruit-based juices: Focus on antioxidant properties-Study approach and update

This paper proposes a perspective literature review of the antioxidant properties in fruit-based juices. The total antioxidant properties due to compounds such as carotenoids, polyphenolic compounds, flavonoids, and tannins as well as the assessment of interactions between natural active compounds and other food matrix components can be seen as the first step in the study of potential health benefits of fruit-based juices. A brief summary is given on the significance of antioxidant properties of fruit juices, the conventional methods for antioxidant activity evaluation, and on the newly emerged sample analysis and data interpretation strategies, that is, chemometric analysis based on spectroscopic data. The effect of fruit processing techniques and the addition of ingredients on the antioxidant properties of fruit-based juices are also discussed.