Progress on research and development of goji berry drying: a review

A systematic UHPLC Q-ToF MS approach for the characterization of bioactive compounds from freeze-dried red goji berries (L. barbarum L.) grown in Serbia: Phenolic compounds and phenylamides

The aim of this study was to identify and characterise different classes of bioactive compounds from freeze-dried red goji berries (RGB) grown in Serbia, using ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC Q-ToF MS). In addition, this study aims to demonstrate the importance of applying the advanced UHPLC Q-ToF MS technique in the identification of various biocompounds. The analysis showed the presence of 28 phenolic compounds, 3 organic acids, and 26 phenylamides. The 2-O-β-d-glucopyranosyl-l-ascorbic acid (AA-2βG) was identified by UHPLC Q-ToF MS and quantified by standardised UHPLC-DAD method. Most of the compounds detected were derivatives of caffeic acid and ferulic acid, followed by quercetin derivatives. Among the phenylamides, several glucosylated caffeoyl and/or dihydrocaffeoyl derivatives of spermidine and spermine were characterized, confirming their recent characterization. Some glycosylated/non-glycosylated putrescine derivatives and caffeoyl-dihydrocaffeoyl-feruloyl spermidines were identified in goji berriesfor the first time. Their tentative structures and fragmentations were proposed.

Sea Buckthorn Pretreatment, Drying, and Processing of High-Quality Products: Current Status and Trends

Sea buckthorn is a kind of berry rich in nutritional and industrial value. Due to its thin skin, juicy pulp, and short shelf life, it is usually preserved via freezing methods or directly processed into sea buckthorn puree after harvest. It can also be dried and processed into products such as dried sea buckthorn fruit, freeze-dried sea buckthorn powder, and sea buckthorn oil. This review, therefore, provides an overview of the existing state of drying and high-quality processing of sea buckthorn. The effects of different pretreatment and drying techniques on the drying characteristics and quality of sea buckthorn and the existing problems of superior-quality processing of sea buckthorn products are summarised. The development trend of sea buckthorn drying methods and the ways to achieve high-quality processing of sea buckthorn products are indicated. These ways are mainly related to the following: (1) The application of combined pretreatment and drying techniques to find a balance between economy, ecology, and efficiency; (2) Introducing new online measurement and control technology into drying equipment; (3) Optimising the existing process to form a complete sea buckthorn industrial chain and develop the sea buckthorn deep-processing industry.

Ultralight sponge made from sodium alginate with processability and stability for efficient removal of microplastics

Due to natural agents and human activities, large quantities of microplastics enter the marine environment. As an emerging pollutant, MPs have attracted worldwide attention and become a great challenge in recent years. Sodium alginate is a kind of natural polysaccharide with non-toxic, stability, and low cost. In this study, sodium alginate sponge was prepared by secondary freeze-drying technology. Alginate sponge contains a large number of hydrophilic groups; thus, alginate sponge has super water-absorbed (the water absorption rate range from 1193-5232%). Meanwhile, the alginate sponge has high porosity of 81.93% and excellent mechanical properties. The removal efficiency of 100 mg·L-1 microplastics by alginate sponge reached up to 92.3%. The 1 mg·L-1 and 10 mg·L-1 microplastics can be completely absorbed in 27 h and 60 h, respectively. The adsorption mechanism of microplastics adsorbed onto alginate sponge included intra-particle diffusion, hydrogen bonds interactions, and π-π interactions. In addition, the adsorption of MPs loaded Cu2+/Na+ by sponge in complex aqueous environments is still significant. This study expands the development prospect of sodium alginate sponge materials in the field of water treatment and provides a new green approach for the removal of microplastics.

Effect of Different Drying Techniques on Total Bioactive Compounds and Individual Phenolic Composition in Goji Berries

In recent years, interest in the consumption of dried goji berries has increased due to its high bioactive properties. Alternative drying methods that provide faster drying and better preservation of bioactive properties should be developed. This study aims to investigate the effect of different drying methods on the drying time and quality characteristics of the goji berry; namely, hot-air drying (HAD), ultrasound-assisted vacuum drying (USVD), vacuum drying (VD), freeze-drying (FD), and ultrasound-pretreated freeze-drying (USFD). The drying kinetic, total phenolic content, antioxidant capacity, phenolic profile, carotenoid profile, and color change of the goji berry fruit were determined. The drying times for VD, USVD, and HAD varied between 275–1330 min. USVD treatment showed faster drying behavior than the other two drying methods. The total phenolic content (TPC) value of dry samples varied between 1002.53–1238.59 mg GAE/g DM. USVD treatments exhibited a higher total phenolic content (TPC) value than all other drying methods. DPPH and CUPRAC values varied between 15.70–29.90 mg TE/g DM and 40.98–226.09 mg TE/g DM, respectively. The total color change (ΔE) value ranged between 4.59 and 23.93 and HAD dried samples showed the highest ΔE of all samples. The results of the phenolic profile were consistent with TPC analysis. HAD caused higher phenolic compound degradation than VD, USVD, and FD. The results of this study showed that different drying techniques significantly affected the drying rate and retention of bioactive components of the goji berry fruit, and the USVD and VD methods could be used as an alternative to the HAD method. This study concluded that USVD and FD could be considered as suitable drying methods and could be used as alternatives to HAD in the drying of goji berries.

Chemical and Biological Properties of Three Poorly Studied Species of Lycium Genus-Short Review

The genus Lycium belongs to the Solanaceae family and comprises more than 90 species distributed by diverse continents. Lycium barbarum is by far the most studied and has been advertised as a “superfood” with healthy properties. In contrast, there are some Lycium species which have been poorly studied, although used by native populations. L. europaeum, L. intricatum and L. schweinfurthii, found particularly in the Mediterranean region, are examples of scarcely investigated species. The chemical composition and the biological properties of these species were reviewed. The biological properties of L. barbarum fruits are mainly attributed to polysaccharides, particularly complex glycoproteins with different compositions. Studies regarding these metabolites are practically absent in L. europaeum, L. intricatum and L. schweinfurthii. The metabolites isolated and identified belong mainly to polyphenols, fatty acids, polysaccharides, carotenoids, sterols, terpenoids, tocopherols, and alkaloids (L. europaeum); phenolic acids, lignans, flavonoids, polyketides, glycosides, terpenoids, tyramine derivatives among other few compounds (L. schweinfurthii), and esters of phenolic acids, glycosides, fatty acids, terpenoids/phytosterols, among other few compounds (L. intricatum). The biological properties (antioxidant, anti-inflammatory and cytotoxic against some cancer cell lines) found for these species were attributed to some metabolites belonging to those compound groups. Results of the study concluded that investigations concerning L. europaeum, L. intricatum and L. schweinfurthii are scarce, in contrast to L. barbarum.

Thermal and Dielectric Properties of Wolfberries as Affected by Moisture Content and Temperature Associated with Radio Frequency and Microwave Dehydrations

Knowledge of the thermal and dielectric properties of wolfberries is essential for understanding the heat transfer and the interaction between the electromagnetic field (10-3000 MHz) and the sample during radio frequency (RF) and microwave (MW) drying. The thermal and dielectric properties of wolfberries were determined as influenced by moisture content from 15.1% to 75.2%, w.b.) and temperature from 25 to 85 °C. The results showed that as the moisture content increased from 15.1% to 75.2% (w.b.), the true density of wolfberries decreased, but the specific heat capacity and thermal conductivity increased with increasing temperature and moisture content. The dielectric properties (DPs) of wolfberries decreased with increasing frequency from 10 to 3000 MHz. The dielectric constant increased with increasing temperature at lower a moisture content (below 45% w.b.) but decreased with increasing temperature at a high moisture content (above 60% w.b.). The cubic and quadratic polynomial models (R² = 0.977 - 0.997) were best for fitting the dielectric constant and loss factor at four representative frequencies of 27, 40, 915, and 2450 MHz, respectively. The penetration depth increased with the decreased frequency, temperature, and moisture content, and was greater at RF frequencies than MW range, making the RF heating more effective for drying bulk wolfberries. These findings offered essential data before optimizing RF or MW dehydration protocols for wolfberries via computer simulation.

Bioactivities and Microbial Quality of Lycium Fruits (Goji) Extracts Derived by Various Solvents and Green Extraction Methods

Goji berries, known for their health-promoting properties, are increasingly consumed around the world, often in the form of naturally- or freeze-dried fruits, further unprocessed. The aim of the study was to obtain dried goji berries extracts, characterized by high bioactivity and safety in terms of microbial contamination for the consumer. In the study, various solvents (water, ethanol, acetone, ethyl lactate, sunflower oil) and green extraction methods (heating and ultrasound-assisted extraction (UAE)) were used. In goji extracts, antioxidant activity and carotenoids content as bioactivity indicators, as well as total number of microorganisms were determined. Boiling of powdered dried goji fruits in water resulted in extracts with the best features, i.e., with high antioxidant properties (2.75−4.06 μmol of Trolox equivalent (TE)/mL), moderate to high content of carotenoids (0.67−1.86 mg/mL), and a reduced number of microorganisms compared with fruits. Extracts in 50% ethanol and 50% acetone were characterized primarily by very high antioxidant activity (3.09−4.90 μmol TE/mL). The high content of carotenoids (0.98−3.79 mg/mL) and high microbial quality (<10 CFU/g) were obtained by extraction in ethyl lactate by the UAE method. The results could be useful in the development of functional food based on goji berry ingredients.

Lycium barbarum (Goji) as functional food: a review of its nutrition, phytochemical structure, biological features, and food industry prospects

Lycium genus (Goji berry) is recognized as a good source of homology of medicine and food, with various nutrients and phytochemicals. Lately, numerous studies have focused on the chemical constituents and biological functions of the L. barbarum L., covering phytochemical and pharmacological aspects. We aim to provide exclusive data on the nutrients of L. barbarum L. fruits and phytochemicals, including their structural characterization, the evolution of extraction, and purification processes of different phytochemicals of L. barbarum L. fruit while placing greater emphasis on their wide-ranging health effects. This review also profitably offers innovative approaches for the food industry and industrial applications of L. barbarum L. and addresses some current situations and problems in the development of L. barbarum L. in deep processing products, which can provide clues for the sustainable development of L. barbarum L. industry.