The recent millennium has witnessed a notable shift in consumer focus towards natural products for addressing lifestyle-related disorders, driven by their safety and cost-effectiveness. Nutraceuticals and functional foods play an imperative role by meeting nutritional needs and offering medicinal benefits. With increased scientific knowledge and awareness, the significance of a healthy lifestyle, including diet, in reducing disease risk is widely acknowledged, facilitating access to a diverse and safer diet for longevity. Plant-based foods rich in phytochemicals are increasingly popular and effectively utilized in disease management. Agricultural waste from plant-based foods is being recognized as a valuable source of nutraceuticals for dietary interventions. Citrus peels, known for their diverse flavonoids, are emerging as a promising health-promoting ingredient. Globally, citrus production yields approximately 15 million tons of by-products annually, highlighting the substantial potential for utilizing citrus waste in phyto-therapeutic and nutraceutical applications. Citrus peels are a rich source of flavonoids, with concentrations ranging from 2.5 to 5.5 g/100 g dry weight, depending on the citrus variety. The most abundant flavonoids in citrus peel include hesperidin and naringin, as well as essential oils rich in monoterpenes like limonene. The peel extracts exhibit high antioxidant capacity, with DPPH radical scavenging activities ranging from 70 to 90%, comparable to synthetic antioxidants like BHA and BHT. Additionally, the flavonoids present in citrus peel have been found to have antioxidant properties, which can help reduce oxidative stress by 30% and cardiovascular disease by 25%. Potent anti-inflammatory effects have also been demonstrated, reducing inflammatory markers such as IL-6 and TNF-α by up to 40% in cell culture studies. These findings highlight the potential of citrus peel as a valuable source of nutraceuticals in diet-based therapies.

This study investigates the combined effect of multi-frequency ultrasound-assisted fermentation on enhancing the functional and nutritional quality of sea buckthorn (Hippophae rhamnoides L.) juice. A defined tri-strain lactic acid bacteria (LAB) consortium; Lactiplantibacillus plantarum, Lacticaseibacillus paracasei, and Lactobacillus helveticus was employed to evaluate its impact on phytochemical enrichment, antioxidant potential, and sensory characteristics. The integrated bioprocess resulted in a substantial increase in total phenolic content (23.8-fold) and total flavonoid content (1.18-fold) compared to the unfermented control. Antioxidant activity showed significant enhancement with DPPH radical scavenging increasing from 88.63 % to 122.73 % and FRAP rising from 100.91 to 566.58 µmol/L. HPLC analysis revealed notable increases in quinic acid (1.29-fold), gallic acid (3.20-fold), and citric acid (7.34-fold), while FTIR, SEM, and XRD analyses confirmed microstructural alterations and improved bioactive accessibility. Sensory evaluation indicated elevated fruity and floral aroma intensities, with scores rising from 2.5 to 4.5. These findings demonstrate that multi-frequency ultrasound coupled with LAB fermentation is an effective, non-thermal approach for enhancing the bioactive, structural, and organoleptic attributes of sea buckthorn juice, supporting its potential as a next-generation functional beverage with broad nutraceutical applications.

Lifestyle-related malfunctions, the “diseases of affluence/civilization,” are emerging largely because of changing living pattern. Due to inflation in medical care cost, nutritionists and health-care professionals have been forced to explicate the notion of functional foods and nutraceuti-cals. Nutraceuticals are substances considered as food or components of food-imparting medicinal or health benefits encompassing prevention or management of diseases. Recent research has shown beneficial therapeutic properties of various traditional plants including garlic, ginger, green tea, black cumin, and onion. The diet-based therapies can be helpful in mitigating various lifestyle-related disparities. In this context, garlic is a powerhouse of nutraceuticals known to possess certain beneficial compounds, such as allicin, that are helpful in ameliorating numerous 236physiological threats. This chapter includes the potential applications and benefits of garlic and its bioactive moieties. The extraction technologies and conditions have also been discussed for better isolation of biologically active agents. Moreover, the prophylactic role of garlic and its major nutraceutical agent allicin against hyperglycemia and dyslipidemia have also been discussed at the end.