Infrared-assisted freeze-drying (IRFD) of açai puree: Effects on the drying kinetics, microstructure and bioactive compounds

Bacterial viability retention in probiotic foods: a review

Probiotics offer substantial health benefits, leading to their increased consumption in various food products. The viability of probiotics is a critical factor that influences the nutritional and therapeutic efficacy of these foods. However, as probiotics often lose viability during production and oral administration, effective preservation and encapsulation technologies are needed to overcome this challenge. This review elucidates the diverse sources and incorporation strategies of probiotics, while systematically analyzing the effects of water transformation (ice front velocity, glass transition temperature, and collapse temperature), processing conditions (food matrix, temperature, and dissolved oxygen), and gastrointestinal challenges (gastric fluid, digestive enzymes, and bile salts) on probiotic viability. Effective strategies to strengthen probiotic viability encompass three primary domains: fermentation processes, production techniques, and encapsulation methods. Specifically, these include meticulous fermentation control (nitrogen sources, lipids, and carbon sources), pre-stress treatments (pre-cooling, heat shock, NaCl stress, and acid stress), optimized lyoprotectant selection (carbohydrates, proteins, and polyols), synergistic freeze-drying technologies (infrared technology, spray drying, and microwave), bulk encapsulation approaches (polysaccharide or protein-based microencapsulation), and single-cell encapsulation methods (self-assembly and surface functionalization). Despite these advancements, targeting specific probiotics and food matrices remains challenging, necessitating further research to enhance probiotic viability.

Characterization of Physicochemical Properties, Bioactivities, and Sensory Attributes of Sea Buckthorn-Fava Bean Composite Instant Powder: Spray-Drying Versus Freeze-Drying Coupled with Carriers

Foods and beverages with health benefits have become increasingly popular with consumers, and fruits and legumes are considered good sources of nutrients. In this study, sea buckthorn and fava bean were used as the main raw materials to prepare sea buckthorn-fava bean composite instant powder (S-FCP). Different drying methods (spray-drying (SD) and freeze-drying (FD)) combined with carriers (maltodextrin (MD) and inulin (INU)) were involved to investigate their effects on physicochemical properties, functional properties, and sensory attributes of instant powder. The results showed that FD better protected the color of the S-FCP and produced particles possessing more porous structures compared to SD; FD-INU (freeze-dried-inulin) had the shortest dissolution time and the largest solubility. In addition, FD-INU had the highest total phenolic and total flavonoid contents and the strongest antioxidant capacity, and FD-INU had better overall organoleptic properties and hypoglycemic potential. Therefore, FD and the use of INU as a carrier are more suitable for the production of the S-FCP. This work provides a promising approach for developing a high-valued instant powder beverage composed of sea-buckthorn/broad bean, which also contributes to the development of the functional food industry.

Advancement and Innovations in Drying of Biopharmaceuticals, Nutraceuticals, and Functional Foods

Drying is a crucial unit operation within the functional foods and biopharmaceutical industries, acting as a fundamental preservation technique and a mechanism to maintain these products' bioactive components and nutritional values. The heat-sensitive bioactive components, which carry critical quality attributes, necessitate a meticulous selection of drying methods and conditions backed by robust research. In this review, we investigate challenges associated with drying these heat-sensitive materials and examine the impact of various drying methods. Our thorough research extensively covers ten notable drying methods: heat pump drying, freeze-drying, spray drying, vacuum drying, fluidized bed drying, superheated steam drying, infrared drying, microwave drying, osmotic drying, vacuum drying, and supercritical fluid drying. Each method is tailored to address the requirements of specific functional foods and biopharmaceuticals and provides a comprehensive account of each technique's inherent advantages and potential limitations. Further, the review ventures into the exploration of combined hybrid drying techniques and smart drying technologies with industry 4.0 tools such as automation, AI, machine learning, IoT, and cyber-physical systems. These innovative methods are designed to enhance product performance and elevate the quality of the final product in the drying of functional foods and biopharmaceuticals. Through a thorough survey of the drying landscape, this review illuminates the intricacies of these operations and underscores their pivotal role in functional foods and biopharmaceutical production.

Comparative elucidation of bioactive and antioxidant properties of red dragon fruit peel as affected by electromagnetic and conventional drying approaches

The effects of near-infrared (NIRD), mid-infrared (MIRD), far-infrared (FIRD), microwave (MWD), and hot air drying (HAD) on drying kinetic, colour, phytochemical composition, and antioxidant activity of red dragon fruit peel (RDFP) was evaluated. Results indicated that drying methods induced varying microstructural and chemical changes on RDFP, significantly influencing moisture removal rates and phytochemical retention. The lowest drying time was observed for MWD, while MIRD presented the highest drying time. FIRD drying was more favourable for retaining TPC, TFC, betacyanin and betaxanthin, while the ascorbic acid content was better retained during MIRD and NIRD. Enhancements in ABTS, CUPRAC and reducing power were associated with FIRD, and NIRD and MIRD enhanced DPPH and HRSA. Overall, chemical modifications induced by drying improved the phytochemical and antioxidant properties but presented adversative effects on ascorbic acid and DPPH. The study presented an essential background for the optimal drying of RDFP.

Novel Efficient Physical Technologies for Enhancing Freeze Drying of Fruits and Vegetables: A Review

Drying is the main technical means of fruit and vegetable processing and storage; freeze drying is one of the best dehydration processes for fruit and vegetables, and the quality of the final product obtained is the highest. The process is carried out under vacuum and at low temperatures, which inhibits enzymatic activity and the growth and multiplication of micro-organisms, and better preserves the nutrient content and flavor of the product. Despite its many advantages, freeze drying consumes approximately four to ten times more energy than hot-air drying, and is more costly, so freeze drying can be assisted by means of highly efficient physical fields. This paper reviews the definition, principles and steps of freeze drying, and introduces the application mechanisms of several efficient physical fields such as ultrasonic, microwave, infrared radiation and pulsed electric fields, as well as the application of efficient physical fields in the freeze drying of fruits and vegetables. The application of high efficiency physical fields with freeze drying can improve drying kinetics, increase drying rates and maintain maximum product quality, providing benefits in terms of energy, time and cost. Efficient physical field and freeze drying technologies can be well linked to sustainable deep processing of fruit and vegetables and have a wide range of development prospects.

Preparation, characterization, identification, and antioxidant properties of fermented acaí (Euterpe oleracea)

Fermentation technology was used to prepare the acaí (Euterpe oleracea) fermentation liquid. The optimal fermentation parameters included a strain ratio of Lactobacillus paracasei: Leuconostoc mesenteroides: Lactobacillus plantarum = 0.5:1:1.5, a fermentation time of 6 days, and a nitrogen source supplemental level of 2.5%. In optimal conditions, the ORAC value of the fermentation liquid reached the highest value of 273.28 ± 6.55 μmol/L Trolox, which was 55.85% higher than the raw liquid. In addition, the FRAP value of the acaí, as well as its scavenging ability of DPPH, hydroxyl, and ABTS free radicals, increased after fermentation. Furthermore, after fermentation treatment, the microstructure, basic physicochemical composition, amino acid composition, γ-aminobutyric acid, a variety of volatile components, and so on have changed. Therefore, fermentation treatment can significantly improve the nutritional value and flavor of the acaí. This provides a theoretical basis for the comprehensive utilization of acaí.

Advances in the Chemistry, Analysis and Adulteration of Anthocyanin Rich-Berries and Fruits: 2000-2022

Anthocyanins are reported to exhibit a wide variety of remedial qualities against many human disorders, including antioxidative stress, anti-inflammatory activity, amelioration of cardiovascular diseases, improvement of cognitive decline, and are touted to protect against neurodegenerative disorders. Anthocyanins are water soluble naturally occurring polyphenols containing sugar moiety and are found abundantly in colored fruits/berries. Various chromatographic (HPLC/HPTLC) and spectroscopic (IR, NMR) techniques as standalone or in hyphenated forms such as LC-MS/LC-NMR are routinely used to gauge the chemical composition and ensure the overall quality of anthocyanins in berries, fruits, and finished products. The major emphasis of the current review is to compile and disseminate various analytical methodologies on characterization, quantification, and chemical profiling of the whole array of anthocyanins in berries, and fruits within the last two decades. In addition, the factors affecting the stability of anthocyanins, including pH, light exposure, solvents, metal ions, and the presence of other substances, such as enzymes and proteins, were addressed. Several sources of anthocyanins, including berries and fruit with their botanical identity and respective yields of anthocyanins, were covered. In addition to chemical characterization, economically motivated adulteration of anthocyanin-rich fruits and berries due to increasing consumer demand will also be the subject of discussion. Finally, the health benefits and the medicinal utilities of anthocyanins were briefly discussed. A literature search was performed using electronic databases from PubMed, Science Direct, SciFinder, and Google Scholar, and the search was conducted covering the period from January 2000 to November 2022.