Survival Analysis to Predict How Color Influences the Shelf Life of Strawberry Leather

Color change of fruit-based products during storage is an important quality parameter to determine their shelf life. In this study, a combination of relative humidity (RH) and illumination was evaluated on the stability of strawberry leathers. Samples were conditioned at 25 °C, in chambers with RH of 22.5% and 52.3% and under two levels of illumination (no illumination and with a light-emitting diode (LED) illumination at 1010 lx). Samples were analyzed during storage by instrumental color measurements, total anthocyanin content, and consumers’ acceptance/rejection of the product color. Current-status survival analysis was performed to estimate the sensory-based shelf-life of the strawberry leather. The chromatic parameters (a* and ΔE* values) and anthocyanin content changed with increasing storage time and RH, fitting a first-order fractional conversion model. Samples conditioned at the higher RH showed a higher reduction of a* values and anthocyanins losses when stored under LED illumination than those without illumination. The increase of RH resulted in a faster increase of the consumer rejection probability and a shorter shelf life of the strawberry leather. For 50% of consumers’ rejection, the sensory shelf life of the strawberry leather equilibrated at 22.5% RH was estimated as at least 54 days, while it was reduced to approximately 2 days at 52.3% RH. The red chromatic parameter (a* value) strongly correlated to the percentage of consumer rejection in all storage conditions, suggesting that this analytical parameter can be useful as a predictor of strawberry leather’s shelf life. Therefore, the results of this study show the applicability of an approach that integrates instrumental and sensory data to acquire faster information on color changes during the storage of strawberry leather and product shelf-life prediction.

The Use of Compost Increases Bioactive Compounds and Fruit Yield in Calafate Grown in the Central South of Chile

Different concentrations of compost applied as organic fertilizer can modify productive, quality, and chemical parameters in several fruit tree species. The objective of this study was to determine the effect of increasing applications of compost on physiological, productive, and quality parameters in calafate fruit during the seasons of 2018–2019 and 2019–2020. The study was conducted on a commercial calafate orchard using a randomized complete block design with four treatments (CK: no compost application, T1: 5 Ton ha−1, T2: 10 Ton ha−1, and T3: 15 Ton ha−1), each with four repetitions. The results did not show statistical significance for stomatal conductance (Gs), quantum yield of PSII, or photosynthetic active radiation (PAR) within treatments. As for fruit yield, a statistical difference was found between the control treatment and T1, which were lower than T2 and T3 in both seasons. The trees reached a higher leaf area index with T2 in both seasons. The highest antioxidant capacity was obtained with T3 and T2 for the first and second season, respectively. Polyphenols and total anthocyanin production showed statistical significance, with a higher content at the second season with T2. It is concluded that the dose under which yield, quality, and nutraceutical content of calafate fruit are optimized is the one used in T2, 10 Ton ha−1.

Application of abscisic acid (S-ABA) at different stages of ripening on color development of ‘Rubi’ table grape

The color of the berries is an important aspect of the quality of table grapes and crucial for marketing. The ‘Rubi’ table grapes grown in the subtropical climate generally lack color intensity due to the inhibition of anthocyanins by high temperatures during ripening. The exogenous application of abscisic acid (S-ABA) can be used to overcome this problem as the accumulation of anthocyanins in the berry skin is regulated by this plant growth regulator. The objective of this study was to assess the effect of the exogenous application of S-ABA at different stages of ripening on color development in ‘Rubi’ table grapes using the soluble solids (SS) content as a marker of ripening. The study was conducted during two seasons in commercial vineyards. The first trial was conducted in Marialva, Parana, Brazil, during the 2019 summer season crop (harvest in December). S-ABA (400 mg L-1) was exogenously applied at different stages of ripening of ‘Rubi’ table grapes (determined by the SS content of the berries): control (without application); SS = 8-9 ºBrix; SS = 10-11 ºBrix; SS = 8-9 ºBrix (two applications; the second one applied 10 days after the first); and SS = 10-11 ºBrix (two applications; the second one applied 10 days after the first). The second trial was conducted in Cambira, Parana, Brazil, during the 2020 off-season crop (harvest in May). S-ABA (400 mg L-1) was exogenously applied at different stages of ripening of ‘Rubi’ grapes: control (without application); SS = 6-7 ºBrix; SS = 7-8 ºBrix; SS = 9-10 ºBrix; SS = 6-7 ºBrix (two applications; the second one applied 14 days after the first); SS = 7-8 ºBrix (two applications; the second one applied 14 days after the first); and SS = 9-10 ºBrix (two applications; the second one applied 14 days after the first). A randomized block design was used as the statistical model with four replications, and each plot consisted of one vine. The variables analyzed were total anthocyanin contents, color index (CIRG), and color attributes (L*, C*, h°, and ΔE) of berry skin. The total anthocyanin accumulation and color attributes of the berries were evaluated every 10 and 7 days after the first application of S-ABA until harvest in the first and second trials, respectively, and the other variables were evaluated at harvest. In the summer-season crop, when the SS content was 8-11 ºBrix, the application of S-ABA increased the concentration of the total anthocyanins 4 times compared to that in the control, improving berry color development. Furthermore, in the off-season crop, when the SS content was 6-10 ºBrix, the application of S-ABA increased the concentration of total anthocyanins 2-3 times compared to that in the control, improving the color attributes of berries. In both crops, a single application of the plant growth regulator was sufficient to intensify the color of the berries.

Effects of Combining the Genes Controlling Anthocyanin and Melanin Synthesis in the Barley Grain on Pigment Accumulation and Plant Development

Anthocyanins and melanins are phenolic pigments of plants and accumulate in seed envelopes of the barley grain, thereby giving them a blue, purple, or black color. To explore the effects of combined accumulation of anthocyanins and melanins in the grain, a barley near-isogenic line (NIL), characterized by simultaneous accumulation in both pigments, was developed using a marker-assisted approach. The presence of both pigments in the grain pericarp was evaluated by light microscopy. Emergence of anthocyanin pigmentation proved to be temporally separated from that of melanin, and the formation of anthocyanin pigments began at an earlier stage of spike maturation. During spike maturation, a significantly higher total anthocyanin content was noted in the created NIL than in the parental anthocyanin-accumulating NIL, indicating a positive influence of the Blp1 gene on the anthocyanin content at some developmental stages. In a comparative analysis of yield components, it was found that the observed differences between the barley NILs are possibly caused by environmental factors, and the presence of pigments does not decrease plant productivity. Our results should facilitate investigation into genetic mechanisms underlying overlaps in the biosynthesis of pigments and into breeding strategies aimed at the enrichment of barley varieties with polyphenols.

Extraction of Anthocyanins from Borage (Echium amoenum) Flowers Using Choline Chloride and a Glycerol-Based, Deep Eutectic Solvent: Optimization, Antioxidant Activity, and In Vitro Bioavailability

Borage flower (Echium amoenum), an annual herb native to the Mediterranean region, is an excellent source of anthocyanins and is widely used in various forms due to its biological activities. In the present study, a choline chloride and glycerol (CHGLY)-based natural deep eutectic solvent (NADES) was applied in order to extract the anthocyanins from borage flowers. The traditional solvents, including water, methanol, and ethanol, were used to evaluate the efficiency of CHGLY. The results showed that CHGLY was highly efficient compared to the traditional solvents, providing the highest amounts of the total anthocyanin content (TAC), total phenolic content (TPC), total flavonoid content (TFC), individual anthocyanins, and antioxidant activity (DPPH radical scavenging (DPPH) and ferric-reducing antioxidant power (FRAP) assays). The most dominant anthocyanin found in studied borage was cyanidin-3-glucoside, followed by cyanin chloride, cyanidin-3-rutinoside, and pelargonidin-3-glucoside. The bioavailability % was 71.86 ± 0.47%, 77.29 ± 0.57%, 80.22 ± 0.65%, and 90.95 ± 1.01% for cyanidin-3-glucoside, cyanidin-3-rutinoside, by pelargonidin-3-glucoside and cyanin chloride, respectively. However, cyanidin-3-glucoside was the anthocyanin compound showing the highest stability (99.11 ± 1.66%) in the gastrointestinal environment. These results suggested that choline chloride and glycerol-based NADES is not only an efficient, eco-friendly solvent for the extraction of anthocyanins but can also be used to increase the bioavailability of anthocyanins.

Effect of growing location on anthocyanin content and total antioxidant capacity of haskap (Lonicera caerulea L.) berry: A preliminary investigation

The haskap has been successfully cultivated in many geographical zones in Canada. We investigated whether the latitude has any impact on the anthocyanin accumulation and total antioxidant capacity in the haskap berry. The measured quality attributes were compared with that of the blueberry. Haskap ‘Aurora’ berries were collected from Yukon, British Columbia, Saskatchewan, and Nova Scotia in Canada, and blueberries were collected from Nova Scotia. Cyanidin-3-O-glucoside (C3G), the most abundant anthocyanin of haskap berry, the total anthocyanins, the total polyphenols, the soluble solids (°Brix), the pH value, the total antioxidant capacity, and the moisture content were determined. The results revealed that the total anthocyanin, total phenolic content, and antioxidant capacity of the haskap range between 88 to 273 mg C3GE/100 g fresh weight (FW), 256 to 442 mg GAE/100 g of FW, and 27 to 52 µmol TE/g FW, respectively. The liquid chromatography-mass spectrometry (UPLC/MS) analysis revealed that the C3G contained in the haskap berry is highly dependent on the harvest stage. Among the samples, the haskap berry harvested on July 19, 2019, from the Yukon had the highest C3G content. Interestingly, the total anthocyanin content of the haskap berry is comparable to that of the lowbush blueberry, but higher than the highbush blueberry. A systematic multi-year experiment employing many cultivars and growing locations is recommended to better understand the latitude effect.

Structural identification and in vitro antioxidant activities of anthocyanins in black chokeberry (Aronia melanocarpa Elliot)

Anthocyanins is a natural edible pigment with many health benefits. The aim of this work was the identification of anthocyanins present in <i>Aronia melanocarpa</i> using mass spectrometric features. The anthocyanins of the <i>A. melanocarpa</i> were analyzed by UV-Vis, HPLC-DAD and LC-EIS/MS methods. The four important anthocyanins were identified as follows: cyanidin-3-galactoside (68.68%), cyanidin-3-arabinoside (25.62%), cyanidin-3-glucoside (5.28%) and cyanidin-3-xyloside (0.42%). Among the four anthocyanin monomers, three anthocyanins with the highest content of <i>A. melanocarpa</i> were selected, and the antioxidant activity was studied with the total anthocyanins. The antioxidant capacity was cyanidin-3-galactoside > total anthocyanin > cyanidin-3-arabinoside > cyanidin-3-glucoside. The activity of the four anthocyanin samples was greater than ascorbic acid. The methodology described in this study will provide an effective tool for anthocyanins identification. Our results suggested that anthocyanins from <i>A. melanocarpa</i> exhibited effective antioxidant activity. These findings may be crucial in future research concerning chokeberry based functional food products.

Physical and chemical properties of roselle extract nanocapsule with inulin, chitosan and maltodextrin as encapsulant

Roselle contains high phenolic compounds, mainly anthocyanins that are not stable with pH, metal ions, light exposure, temperature, oxygen, and enzymatic activity. The stability of phenolic compounds can be improved by nanoencapsulation. This research was aimed to evaluate the effect of inulin, inulin-chitosan and inulin-chitosan-maltodextrin with varying concentrations as encapsulants towards the physicochemical properties and encapsulation efficiency of nanocapsules product by spray drying. Roselle extract nanocapsules were prepared using various types and concentrations of encapsulants (inulin, inulin-chitosan and inulin-chitosan-maltodextrin). The solubility of nanocapsules ranged from 69.31 - 83.2%, while the hygroscopicity of nanocapsules was varied, approximately 17.89 - 23.79%. Nanocapsules moisture content was approximately 2.83 - 4.27%, while the total phenolic content of nanocapsules ranged from 6.74 - 13.41 mg GAE/g DW. The total anthocyanin of roselle extract nanocapsules was approximately 2.25 - 4.82 mg/g DW. The encapsulation efficiency of phenolic compounds in this study were approximately 60.31 - 77.13%. Nanocapsules with inulin-chitosan-maltodextrin (2.4%-2.4%-0.2%) had good properties of nanocapsules such as good solubility, high total phenolic content and total anthocyanin content. Nanocapsules with 5% inulin and inulinchitosan-maltodextrin (2.4%-2.4%-0.2%) had particle size of 641.4 and 411.1 nm respectively. The nanocapsules had a spherical shape, smooth surfaces but also a few had indentations.

Study of the Phenolic Compound Profile of Arbutus unedo L. Fruits at Different Ripening Stages by HPLC-TQ-MS/MS

Arbutus unedo L. berries have traditionally been used as edible and medicinal fruits in folk medicine for the treatment of some pathologies. Besides their good nutritional properties, these berries are rich in bioactive compounds. Accordingly, a HPLC-triple quadrupole (TQ)-MS/MS method was developed and validated for the first time to characterize the changes produced in the phenolic composition profile of A. unedo L. fruits through three ripening stages. Several hydroxycinnamic and hydroxybenzoic acids were detected, gallic acid being the highest phenolic acid quantified. Quercetin, quercetin-3-β-glucoside, rutin, and kaempferol were found in similar amounts at the different maturity stages. High amounts of (+)-catechin, procyanidin B2, epigallocatechin, and (−)-epigallocatechin gallate were observed in the unripe fruits. Naringin and vitexin were also quantified. Stilbenes, such as trans-resveratrol and trans-piceid, were identified for the first time in these fruits. Total phenolic compounds, total anthocyanin compounds, and radical scavenging activity were also determined in the fruits harvested at different years in several locations of the Iberian Peninsula at different ripening stages. The results confirmed that these fruits are an excellent source of these bioactive compounds (mainly flavanols) with high antioxidant activity, which could be used as a new source for preparation of nutraceutical or functional foods.