Bio-functional properties of Jilungin (Terminalia canescens).

Jilungin (Terminalia canescens) is a native Australian plant and the Indigenous "Nyul Nyul" people of the  Kimberley region of Western Australia use its leaves to make herbal tea. Due to the rise in the popularity of drinking Jilungin tea among the consumers in Australia and internationally, it is important to study the nutritional and health-beneficial properties as well as safety of Jilungin leaves. This study aims to determine the nutritional composition, anti-nutritional factors, antimicrobial and antidiabetic properties of Jilungin leaves. Also, the phytochemical profiling using UHPLC-MS/MS (Ultra-performance liquid chromatographymass spectrometry) and antioxidant activity of Jilungin methanolic extracts and herbal infusion were investigated. The safety of the leaves and infusion was also investigated by using in vitro mammalian cell lines (Caco2, HT29, and HepG2) through cell viability assays. The leaves are rich in dietary fiber (43.9%) and linoleic acid (30.4% of total fatty acids). Phytochemical profiling revealed ellagic acid, geraniin, pedunculagin, and punicalagin as the major bioactive compounds. The results also demonstrated that Jilungin has strong antioxidant and antidiabetic activities. A significant (p < 0.01) strong positive correlation was observed between the high antioxidant activity of Jilungin infusion with the major bioactive compounds. Jilungin extracts (50 mg/mL) exhibited strong antimicrobial activity against Staphylococcus aureus and Bacillus cereus. Its infusion and methanolic extract were safe on the studied cell lines (Caco-2, HT29, and HepG2) at higher concentrations of 66.6 and 98 mg/mL, respectively. Therefore, Jilungin teas or infusions could be a safe and effective way to promote health and well-being. PRACTICAL APPLICATION: Jilungin tea is very popular among consumers in Australia and is gaining popularity worldwide. The current study will increase knowledge on the nutritional aspects and safety of the Jilungin use.

The Effects of Nitrogen Application and Varietal Variation on the Product Quality and In Vitro Bioaccessibility of Bioactive Compounds of Baby Spinach Varieties Grown in a Soilless Growth Medium.

Baby spinach is becoming increasingly popular as a salad ingredient and needs high fertiliser rates to grow well and attain higher-quality leaves (dark green leaves). Chemical fertilisers, especially nitrogen (N), boost yields. There are many risks associated with nitrogen fertilisation. Additionally, spinach contains phenolic compounds and carotenoids. Nitrogen fertilisation affects growth, development, yield and metabolites. This study examined the impact of lower concentrations of N (0, 30, 60, 90, 120, 150 mg/L) on yield and colour properties [light intensity (L*) colour coordinates, unique for green colour (a*) and yellow colour (b*)], as well as the impact of varying N concentrations on the total phenolic content and p-coumaric acid, quercetin, ferulic acid, kaempferol, lutein, zeaxanthin, ß-carotene and antioxidant activities in the baby spinach varieties 'Acadia', 'Crosstrek' and 'Traverse', and it was established that N fertilisation improves phytochemical bioaccessibility and antioxidant activity. In a split strip plot design, three baby spinach varieties were treated with different N concentrations, including 0, 30, 60, 90, 120 and 150 mg/L. For 40 days, three baby spinach varieties were grown on soilless Mikskaar Professional substrate 300. During both seasons, 'Crosstrek' had the highest fresh mass (921.4 g/m2, 856.3 g/m2) at 120 mg/L N, while 'Traverse' had the highest fresh mass at 554.8 g/m2 and at 564.3 g/m2 at 90 mg/L N and did not differ significantly from 90 to 150 mg/L N during either season. During both seasons, 'Acadia' at 90 mg/L N increased fresh mass to 599 g/m2 and 557.9 g/m2. The variety × N supply interaction significantly affected the leaf colour; chlorophyll content across seasons; the levels of bioactive compounds, p-coumaric acid, quercetin, ferulic acid, kaempferol, lutein, zeaxanthin and ß-carotene in spinach varieties; the in vitro bioaccessibility; and the antioxidant activity. Varietal differences influenced the bioaccessibility of phenolic compounds and carotenoid components. The appropriate N levels can be used during plant cultivation to optimise the bioaccessibility of this spinach variety. Thus, fertilising 'Traverse' with 90 mg/N mL increased the in vitro bioaccessibility of ß-carotene (35.2%), p-coumaric acid (7.13%), quercetin (8.29%) and ferulic acid (1.92%) without compromising the yield.

Influence of Harvesting Stages on Phytonutrients and Antioxidant Properties of Leaves of Five Purple-Fleshed Sweet Potato (Ipomoea batatas) Genotypes.

Sweet potatoes (Ipomoea batatas) are highly profitable, contribute to food security, and their leaves rich in phytonutrients. This study examined the optimal leaf harvesting stage by harvesting newly formed leaves (leaves 1 to 5) to achieve the highest concentration of carotenoids, phenolic compounds, antioxidant properties and mineral content. Leaves of five purple-fleshed sweet potato genotypes '2019-11-2' and '2019-1-1', 'Purple-purple', and from the USA '08-21P' and '16-283P' were harvested based on tuber life cycle [vegetative 8 weeks after planting (VS-8WAP), tuber initiation (TIS-12WAP), and tuber maturation phases (TMS-16WAP)]. At the 8WAP stage, leaves of genotype '2019-11-2' had the highest concentrations of cyanidin-caffeoyl-sophoroside-glucoside (17.64 mg/kg), cyanidin-caffeoyl-feruloyl-sophoroside-glucoside (41.51 mg/kg), peonidin-caffeoyl-hydroxybenzoyl-sophoriside-glucoside (45.25 mg/kg), and peonidin caffeoyl-feruloyl-sophoriside-glucoside (24.47 mg/kg), as well as antioxidant scavenging activity. In contrast, 'Purple-purple' harvested at TIS-12WAP showed the highest concentration of caffeoylquinic acid derivatives. Zeaxanthin, lutein, all trans-ß-carotene, and cis-ß-carotene are the most abundant carotenoids in genotype '08-21P' at VS-8WAP. As a result, local genotypes '2019-11-2' harvested at 8WAP and 'Purple-purple' harvested at 12WAP are potential sources of anthocyanins and caffeoylquinic acid derivatives. Conversely, USA's genotype '08-21P' at the VS-8WAP stage is an excellent source of carotenoids. The leaves of USA's '08-21P' genotype and the local '2019-11-2' genotype at TMS-16WAP exhibited the highest content of Fe and Mn, respectively. The study identified the optimal leaf stage for consumption of leaves and for use as a functional ingredient.

Phytonutritional Composition and Antioxidant Properties of Southern African, Purple-Fleshed Sweet Potato (Ipomoea batatas (L.) Lam.) Storage Roots.

Purple sweet potatoes (Ipomoea batatas (L.) genotype) in Southern Africa have a phytonutritional composition and antioxidant properties that can increase incomes and improve nutrition. This study compared the phytonutrient composition and antioxidant properties of four purple-colour sweet potato genotypes (local Purple-purple, '2019-1-1', and USA genotypes, '08-21P' and '16-283P'). These purple sweet potato genotypes were characterised by UPLC/QTOF/MS and 16 phenolic compounds were identified. Purple-purple (very dark purple) showed the highest concentration of cyanidins and peonidin derivatives. Chlorogenic acid derivatives were highest in the genotype '16-283P'. 'Puple-purple' and '16-283P' displayed the strongest antioxidant power and scavenging activities. Diaffeoylquinic acid isomer 1 was identified as the marker candidate for distinguishing the four purple sweet potato genotypes. Southern Africa's highest-protein sweet potato genotypes are Purple-purple (28.81 g/100 g) and '08-21 P' (24.31 g/100 g). A 13.65 g portion of '2019-1-1' would meet the Recommended Dietary Allowance (RDA) for iron for men, while 25.59 g would meet the RDA for children, and 30.72 g would meet the RDA for women. The sweet potato root of genotype '2019-1-1' provides 31.43 g of Zn per day for children and 22.86 g for adults. The roots of local cultivar Purple-purple can be used as functional food ingredients.

Utilizing Xanthan Gum Coatings as Probiotic Bacteria Carriers to Enhance Postharvest Quality and Antioxidants in Fresh-Cut Cantaloupe and Honeydew (Cucumis melo L.) Melons.

Due to spoilage microflora and browning, minimally processed fresh-cut fruits have a short shelf life, and over the years, studies have shown the potential of using edible coatings to extend the shelf life and improve the safety of fresh-cut fruits. Recently, there has been a rise in research on the incorporation of probiotics in edible coatings due to the bespoke health and biopreservation benefits they impart. Therefore, in this study, lactobacillus strains (Lactiplantibacillus plantarum 75 and Bifidobacterium longum) were incorporated into a xanthan edible coating to enhance color retention, sensory properties, antioxidant retention (ascorbic acid, carotenoids, total phenols), and antioxidant activity (FRAP antioxidant power, ABTS scavenger activity) of fresh-cut cantaloupes and honeydew cucumis melo L. melons during cold storage at 5 C and 85% RH for five days. The edible coating was prepared by mixing 0.5% xanthan gum, 1% glycerol, and 2% citric acid solution with L. plantarum 75 (LAB 75) and Bifidobacterium longum bacteria separately, and the final lab count for each strain was made to be 8.0 log CFU/mL. Stable probiotic coatings with ζ-potential of between -39.7 and -51.4 mV and a PdI of 1 were developed, and the incorporation of the probiotic bacteria into the coating was justified using FTIR analysis. The probiotic coatings showed a typical pseudoplastic behavior, in which the viscosity curves fall as the shear rate increases. Thermal stability analysis showed a continuous and multi-step weight reduction in this work, illustrating how the edible coating components interact. The survival of both Lactobacillus strains was recorded on day 5. Both freshly cut melons coated with xanthan and loaded with Lactobacillus strains retained a sufficient quantity of probiotics at the end of storage, while L. plantarum 75 (7 log CFU/g for cantaloupe and 8 log CFU/g for honeydew) retained the highest viability compared to B. longum (6 log CFU/g for cantaloupe and 7 log CFU/g for honeydew). In comparison to the coated and uncoated control samples, the inclusion of L. plantarum 75 in xanthan coatings significantly retained the color properties, pigments (total chlorophyll and carotenoids), ascorbic acid, total phenols, and antioxidant activity (FRAP, DPPH, and ABTS). The overall acceptability of fresh cuts of cantaloupe and honeydew melons coated with xanthan gum loaded with L. plantarum 75 was higher than that of other treatments. Thus, xanthan gum loaded with L. plantarum 75 coating is most suitable for reducing postharvest losses in fresh cuts of honeydew melons and cantaloupe, which will help preserve antioxidant and bioactive properties. The xanthan gum loaded with L. plantarum 75 coatings exhibited the highest preservation impact; therefore, it can be recommended for the fresh-cut industry.

In-vitro colonic fermentation of Kakadu plum (Terminalia ferdinandiana) fruit powder: Microbial biotransformation of phenolic compounds and cytotoxicity.

Kakadu plum (Terminalia ferdinandiana) (KP) is an indigenous fruit used as a functional ingredient in powdered form. Three KP doses (1, 2.5 and 5 g) were digested in a dynamic in vitro gut digestion model over 48 h. Faecal water digests from the colonic reactors were assessed for total soluble polyphenols (TSP), ferric reducing antioxidant power (FRAP), phenolic metabolites and short-chain fatty acids (SCFAs). Effects of digests on cell viability were tested against Caco-2 intestinal and HepG2 hepatic cells. All doses of KP fermentation produced castalagin, corilagin, chebulagic acid, chebulinic acid, and gallic acid. TSP and FRAP significantly increased in 5 g KP digests at 0 and 48 h of fermentation. SCFA concentrations significantly increased after 48 h. Cytotoxic effects of 2.5 and 5 g KP digests diminished significantly after 12 h. Overall, colonic fermentation increased antioxidant activity and polyphenolic metabolites of 5 g KP powder for 48 h.

In Vitro Antioxidant Activity, Bioaccessibility, and Thermal Stability of Encapsulated Strawberry Fruit (Fragaria × ananassa) Polyphenols.

Bioactive compounds in red fruits, such as strawberries, are vulnerable to digestion, and encapsulation has become an alternative for their protection. This study aims at encapsulating strawberry juice (SJ) by freeze-drying with pea protein and okra mucilage (SJPO), pea protein and psyllium mucilage (SJPP), and pea protein, psyllium mucilage, and okra mucilage (SJPPO) and investigating the in vitro release. The highest encapsulation efficiency was observed in capsule SJPPO (95.38%) and the lowest efficiency in SJPO (82.45%). Scanning electron microscopy revealed an amorphous glassy structure for the structure of the strawberry microcapsules, and X-ray diffraction confirmed that observation. However, X-ray diffraction further showed that SJPPO was crystalline, indicating a tighter crosslinking density than the other microcapsules. Fourier transform infrared spectroscopy showed peaks at 3390 and 1650 cm-1, confirming the presence of polyphenols and polysaccharides in the strawberry microcapsules. Thermal stability was higher for SJPPO, and the observed thermal transitions were due to the bonds formed between the polymers and polyphenols. Pelargonidin 3-glucoside, cyanidin 3-glucoside, cyanidin, delphinidin, malvidin 3-glucoside, ellagic acid, chlorogenic acid, catechin, and kaempferol were identified in the strawberry microcapsules. Digestion affected the compounds' content; the bioaccessibility for SJ was 39.26% and 45.43% for TPC and TAC, respectively. However, encapsulation improved the bioaccessibility of both TPC (SJPP, 51.54%; SJPO, 48.52%; and SJPPO, 54.39%) and TAC (SJPP, 61.08%; SJPO, 55.03%; and SJPPO, 71.93%). Thus, encapsulating pea protein isolate, psyllium mucilage, and okra mucilage is an effective method to facilitate targeted release and preserve the biological activities of fruits.

A Review of Phytochemicals and Bioactive Properties in the Proteaceae Family: A Promising Source of Functional Food.

In recent decades, natural plant-based foods have been increasingly used to improve human health due to unhealthy modern dietary patterns, such as the consumption of foods high in sugar and fat. Many indigenous species have been used by Aboriginal peoples for their food and therapeutic properties. Thus, it is important to understand the health-enhancing bioactive profile of Australian indigenous species. The Proteaceae family, such as the genera of Protea, Macadamia, and Grevillea, have been commercially used in the horticulture and food industries. Researchers have reported some findings about Persoonia species, one of the genera in the Proteaceae family. The aim of this review was to provide an overview of the family Proteaceae and the genus Persoonia, including distribution, traditional and commercial uses, phytochemicals, bioactive properties, potential opportunities, and challenges. In this review, bioactive compounds and their properties related to the health benefits of the Proteaceae family, particularly the Persoonia genus, were reviewed for potential applications in the food industry.

Influence of Fermentation on Functional Properties and Bioactivities of Different Cowpea Leaf Smoothies during In Vitro Digestion.

This study investigated the effects of Lactiplantibacillus plantarum 75 (LAB 75) fermentation at 37 °C for 48 h on the pH, total soluble solids (TSS), colour, total titratable acidity (TTA), carotenoids, and bioactivities of cowpea leaf smoothies from three cultivars (VOP 1, VOP 3, and VOP 4). Fermentation reduced the pH from 6.57 to 5.05 after 48 h. The TTA increased with the fermentation period, whilst the TSS reduced. Fermentation of the smoothies resulted in the least colour changes (∆E) in VOP 1 after 48 h. Fermentation of cowpea smoothies (VOP 1, VOP 3, and VOP 4) improved the antioxidant capacity (FRAP, DPPH, and ABTS), which was attributed to the increase in total phenolic compounds and carotenoid constituents in all of the fermented cowpea smoothies. VOP 1 was further selected for analysis due to its high phenolic content and antioxidant activity. The VOP 1 smoothie fermented for 24 h showed the lowest reduction in TPC (11%) and had the highest antioxidant (FRAP, DPPH, and ABTS) activity. Ltp. plantarum 75 was viable and survived the harsh conditions of the gastrointestinal tract, and, hence, could be used as a probiotic. VOP 1 intestinal digesta showed significantly higher glucose uptake relative to the undigested and the gastric digesta, while the gastric phase had higher levels of α-amylase and α-glucosidase compared to the undigested samples.

Bioactive Properties of Kakadu Plum-Blended Products.

Kakadu plum (Terminalia ferdinandiana), endemic to Australia, is growing in popularity due to its high levels of vitamin C and strong antioxidant properties. In this study, Kakadu plum fruit powder was used as a functional food ingredient with other plant materials to develop value-added products to enhance their nutritional and commercial value. The present study determined the bioactive properties of nine products, including three Kakadu plum fruit powder samples produced from different processing batches and five Kakadu plum-blended products. Vitamin C, the total phenolic content, and the ellagic acid content were determined. Bioactive properties such as antioxidant, antidiabetic, and antimicrobial assays were also performed. Cytotoxicity was tested to obtain more specific product information regarding food safety. Kakadu plum-blended products showed lower cytotoxicity and lower bioactive properties (antioxidant and antibacterial activities) in comparison to Kakadu plum powder. However, overall, most of the bioactive properties were shown to be higher in the blends when compared with the commercial blueberry powder as a benchmark antioxidant product. Therefore, there is great potential for Kakadu plum to contribute to the growing functional food and ingredient markets.

Quality Assessment of Burdekin Plum (Pleiogynium timoriense) during Ambient Storage.

Pleiogynium timoriense, commonly known as Burdekin plum (BP), is among many Australian native plants traditionally used by Indigenous people. However, only limited information is available on the nutritional and sensory quality of BP grown in Australia as well as its changes during storage. Therefore, this study evaluated the quality of BP during one week of ambient storage (temperature 21 °C, humidity 69%). Proximate analysis revealed a relatively high dietary fiber content in BP (7-10 g/100 g FW). A significant reduction in fruit weight and firmness (15-30% and 60-90%, respectively) with distinguishable changes in flesh color (ΔE > 3) and an increase in total soluble solids (from 11 to 21 °Brix) could be observed during storage. The vitamin C and folate contents in BP ranged from 29 to 59 mg/100g FW and 0.3 to 5.9 µg/100g FW, respectively, after harvesting. A total phenolic content of up to 20 mg GAE/g FW and ferric reducing antioxidant power of up to 400 µmol Fe2+/g FW in BP indicate a strong antioxidant capacity. In total, 34 individual phenolic compounds were tentatively identified in BP including cyanidin 3-galactoside, ellagic acid and gallotannins as the main phenolics. Principle component analysis (PCA) of the quantified phenolics indicated that tree to tree variation had a bigger impact on the phenolic composition of BP than ambient storage. Sensory evaluation also revealed the diversity in aroma, appearance, texture, flavor and aftertaste of BP. The results of this study provide crucial information for consumers, growers and food processors.

Valorisation of Three Underutilised Native Australian Plants: Phenolic and Organic Acid Profiles and In Vitro Antimicrobial Activity.

Tasmannia lanceolata, Diploglottis bracteata and Syzygium aqueum are understudied native Australian plants. This study aimed to characterise the non-anthocyanin phenolic and organic acid profiles of the aqueous extracts obtained from the leaves of T. lanceolata and fruits of D. bracteata and S. aqueum by UHPLC-Q-Orbitrap-MS/MS and UHPLC-TQ-MS/MS. A total of 39, 22, and 27 non-anthocyanin polyphenols were tentatively identified in T. lanceolata, D. bracteata, and S. aqueum extracts, respectively. Furthermore, sugars and ascorbic acid contents as well as in vitro antioxidant and antimicrobial activities of the extracts were determined. Response surface methodology was applied to achieve an extract blend with a strong inhibitory effect against Pseudomonas viridiflava, the main cause of soft rot in vegetables, Bacillus subtilis, Rhodotorula diobovata and Alternaria alternata. The identified compounds including organic acids (e.g., quinic, citric and malic acids) and polyphenols (e.g., catechin, procyanidins, and ellagitannins) might contribute to the observed antimicrobial activity. Furthermore, this study provides the most comprehensive phenolic profiles of these three underutilised native Australian plants to date.

In Vitro Release of Anthocyanins from Microencapsulated Natal Plum (Carissa macrocarpa) Phenolic Extract in Alginate/Psyllium Mucilage Beads.

Natal plum (Carissa macrocarpa) contains anthocyanins, cyanidin 3-O-ß-sambubioside (Cy-3-Sa), and cyanidin 3-O-glucoside (Cy-3-G) that possess great bioactive properties. During in vitro gastrointestinal digestion, Cy-3-Sa and Cy-3-G are highly sensitive to pH changes and have low bioaccessibility rates of 7.9% and 22%, respectively. This study aimed to therefore use microencapsulation techniques to improve the bioaccessibility of Cy-3-Sa and Cy-3-G. The crude anthocyanin-rich extract was extracted from freeze-dried Natal plum fruit using ultrasonic-assisted ethanol extraction. The anthocyanin-rich extract was encapsulated using the ionic gelation method. Four distinct carrier agents, namely sodium alginate, pectin, xanthan gum and psyllium mucilage were used to form the wall materials. Encapsulation efficiency was highest for alginate/psyllium mucilage beads (93.67%), while alginate showed the least efficiency (86.80%). Scanning Electron Microscopy revealed a cracked and porous structure for the Natal plum extract and a continuous smooth structure for all the beads. Fourier transform infrared spectroscopy showed peaks at 3300 and 1610 cm-1, confirming the presence of polyphenols and polysaccharides in all beads. Thermal stability was higher for the alginate/psyllium mucilage beads and the observed thermal transitions were due to the bonds formed between the polymers and the polyphenols. Alginate beads combined with xanthan gum, pectin, and psyllium mucilage showed a prolonged release of anthocyanins compared to alginate in vitro alone. The highest anthocyanin bioaccessibility was obtained from alginate/psyllium mucilage beads (85.42 ± 1.03%). The results showed the effectiveness of alginate/psyllium mucilage beads in improving stability and in vitro anthocyanin release.

The Bioaccessibility and Antioxidant Activities of Fermented Mango Cultivar Juices after Simulated In Vitro Digestion.

The purpose of this study was to investigate the bioaccessibilities of total phenolic compounds, carotenoid profile, antioxidant activity, and Lactic acid bacteria (LAB) survival in fermented mango juice (MJs) obtained from three mango cultivars after exposure to an in vitro gastrointestinal digestion model. The MJs from three cultivars ('Sabre', 'Peach', and 'Tommy Atkins') were fermented using Lactiplantibacillus plantarum 75 (L75), Leuconostoc pseudomesenteroides 56 (L56), and their combination (L56 + 75). Fermented MJs were digested and fractions: gastric (GF), intestinal (IF), and dialysis (DF) were analyzed for total polyphenolic content (TPC), antioxidant activity (FRAP), 1-diphenyl-2-picrylhydrazyl (DPPH), and 2.2-azinobis-3-ethyl-benzothiazoline-6-sulfonic acid (ABTS). In addition, the carotenoid content and the LAB population were determined from the GF and IF. After digestion, TPC decreased while fermentation improved its bioaccessibility. L75-fermented 'Sabre' MJs had the highest bioaccessible TPC in the GF (75.65%), IF (50.10%), and DF (32.52%) while L56 'Peach' MJs increased the ß-carotene bioaccessibility by 1.32-fold at GF and IF (1.21-fold). When compared to the other two juices, 'Sabre' and 'Peach' MJs fermented with L75 showed the highest IC50 values for DPPH and ABTS. Generally, L75-fermented 'Sabre' MJs had the highest LAB survival at both GF (7.57 Log CFU/mL) and IF (7.45 Log CFU/mL) and hold potential as probiotic juices. L56-fermented 'Sabre' MJs would ensure the delivery of four times the carotenoid recommended dietary allowance (RDA) to a target site in the body while L75-fermented 'Peach' MJs could be used to effectively counteract oxidants in the body system.

Hydrolysable tannins, physicochemical properties, and antioxidant property of wild-harvested Terminalia ferdinandiana (exell) fruit at different maturity stages.

Terminalia ferdinandiana Exell., also known as Kakadu plum, is a wild-harvested native Australian fruit with limited information on how maturity is affecting the phytonutritional properties and bioactivities of the fruit. Thus, this study investigated changes in hydrolysable tannins, phenolic acids, sugar profile, standard physicochemical parameters, and antioxidant-scavenging capacity of wild-harvested Kakadu plum fruits at four different maturity stages, from immature to fully mature. Fruits harvested <25, 25-50, 50-75, and 75-100% degree of fullness were classified as highly immature (stage 1), immature (stage 2), semi-mature (stage 3), and fully mature (stage 4), respectively. Results showed that chebulagic acid, geraniin, chebulinic acid, castalagin, punicalagin, and gallic acid continuously decreased during fruit maturity, while elaeocarpusin, helioscopin B, corilagin, 3,4,6-tri-O-galloyl-S-glucose, and ellagic acid increased at the beginning of fruit growth (from stage 1 to 2), but decreased when the fruits reached their full maturity (stage 4). The levels of hydrolysable tannins and phenolic acids in fully mature fruits (stage 4) were significantly (p ≤ 0.05) lower than that in their immature counterparts (stages 1 and 2). Total phenolic content (TPC) and DPPH antioxidant radical-scavenging activity did not vary significantly between different maturity stages. Pearson's correlation coefficient test indicated that TPC and DPPH positively (p ≤ 0.05) correlate with most of the studied tannin compounds. Sugars (glucose, fructose, and sucrose), total soluble solid content, and titratable acidity increased during the fruit development. Furthermore, principal component analysis (PCA) revealed the difference between the immature and mature samples, based on their nutritional profile and bioactive compounds. The PCA results also suggested a considerable variability between the individual trees, highlighting the challenges of wild-harvest practice.

Antioxidant Activities of Co-Encapsulated Natal Plum (Carissa macrocarpa) Juice Inoculated with Ltp. plantarum 75 in Different Biopolymeric Matrices after In Vitro Digestion.

Biopolymeric systems that co-encapsulate probiotics and bioactive compounds ensure timely delivery in the gastrointestinal tract. Cyanidin 3-sambubioside is the dominant anthocyanin in Natal plum (Carissa macrocarpa). This study aims at the co-encapsulation of Natal plum (Carissa macrocarpa) juice inoculated with Lactiplantibacillus plantarum 75 (Ltp. plantarum 75) by freeze-drying using pea protein isolate, maltodextrin, and psyllium mucilage and evaluating their release in vitro. An encapsulation efficiency of >85% was noted in lactic acid bacteria (LAB) survival and anthocyanin content. Freeze-drying produced pinkish-red powder, rich in polyphenols and LAB (>6 Log CFU mL−1) after 14 days of storage. Natal plum juice + maltodextrin + pea protein isolate + psyllium mucilage + Ltp. plantarum 75 (NMPeaPsyB) showed the highest LAB population (6.74 Log CFU mL−1) with a survival rate of 81.9%. After digestion, NMPeaPsyB and NMPeaPsy had the highest LAB survival (>50%) at 67.5% and 67.5 ± 0.75%, respectively, and the highest bioaccessibility of cyanidin 3-sambubioside in Natal plum juice than the other co-encapsulation with other biopolymers. NMPeaPsy and NMPeaPsyB showed phenolic stability in the gastric phase and controlled release in the intestinal simulated phase. The antioxidant activities had strong correlations with cyanidin 3-sambubioside. The results confirmed that microencapsulation is important for improving stability and allowing for the development of functional foods.

Influence of different rootstocks on quality and volatile constituents of cantaloupe and honeydew melons (Cucumis melo. L) grown in high tunnels.

Two rootstock crosses of sweet melon and watermelon (Cucurbita moschata × Cucurbita maxima hybrids), 'Kickstart' and 'Carnivor', grafted onto four melon cultivars (cantaloups; 'Majestic', 'Hunter', 'Honeygoal' and 'Honeyval') were evaluated for quality, phytonutrient composition and volatile compounds in the 2020 and 2021 growing season at two harvests. Grafted fruits showed higher SSC/TA ratio, and antioxidant scavenging activity. Grafted 'Majestic/Carnivor' and 'Honeyval/ Carnivor' melons significantly increased the ascorbic acid content than the controls. 'Majestic/Carnivor' melons showed the highest ß- carotene and lutein than the controls. PLS-DA score plots discriminated the grafted cantaloupes and honeydew melons from controls based on the concentration of volatile compounds. Hexyl acetate and hexadecane respectively discriminated the grafted cantaloups and honeydew melons from ungrafted fruits. 'Carnivor' rootstocks showed higher expression of volatiles in the grafted cantaloupes and honeydew melons in the heat map. Panellists preferred Majestic/Carnivor' and 'Honeyval/ Carnivor' melons.

Comparison of Caffeoylquinic Acids and Functional Properties of Domestic Sweet Potato (Ipomoea batatas (L.) Lam.) Storage Roots with Established Overseas Varieties.

Root samples of sweet potato varieties originating from South Africa ('Ndou', 'Bophelo', 'Monate', and 'Blesbok'), the USA ('Beauregard'), and Peru ('199062.1') were analyzed using ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC/QTOF/MS) and chemometrics to characterize and compare the locally developed varieties with well-known established overseas varieties. The highest total phenol content was detected in 'Bophelo', followed by 'Beauregard' and Peruvian variety '199062.1'. The Orthogonal Projections to Latent Structures Discriminant Analysis (OPLS-DA) model classified the storage roots of six sweet potato varieties into two clusters. In the OPLS-DA scatter plot, one cluster, which included Peruvian variety '199062.1', was separated from the others. L-tryptophan and 3-caffeoylquinic acid (CQA) showed variable importance in projection (VIP) scores greater than 1.5. Based on the OPLS-DA-S-plot, L-tryptophan separated the other varieties from Peruvian variety '199062.1'. Peruvian variety '199062.1' contained higher concentrations of CQA (1,3-diCQA, 1,4-diCQA, 3,5-diCQA, 4,5-diCQA, 3-CQA, and 5-CQA) and 5-hydroxy-6-methoxycoumarin 7-glucoside than other varieties. Among all sweet potato varieties analyzed, Peruvian variety '199062.1' showed the highest ferric reducing antioxidant power (2,2-diphenyl-1-picryl-hydrazyl-hydrate) free radical scavenging activity, and [2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonate)] scavenging activity. Among the local sweet potato varieties, 'Bophelo' has the greatest potential for commercialization as it is the richest source of CQA.