Changes in the contents of anthocyanins and other compounds in blackberry fruits due to freezing and long-term frozen storage

Effects of Anthocyanins on Components of Metabolic Syndrome-A Review

Metabolic syndrome (MetS) is a significant health problem. The co-occurrence of obesity, carbohydrate metabolism disorders, hypertension and atherogenic dyslipidaemia is estimated to affect 20-30% of adults worldwide. Researchers are seeking solutions to prevent and treat the conditions related to MetS. Preventive medicine, which focuses on modifiable cardiovascular risk factors, including diet, plays a special role. A diet rich in fruits and vegetables has documented health benefits, mainly due to the polyphenolic compounds it contains. Anthocyanins represent a major group of polyphenols; they exhibit anti-atherosclerotic, antihypertensive, antithrombotic, anti-inflammatory and anticancer activities, as well as beneficial effects on endothelial function and oxidative stress. This review presents recent reports on the mechanisms involved in the protective effects of anthocyanins on the body, especially among people with MetS. It includes epidemiological data, in vivo and in vitro preclinical studies and clinical observational studies. Anthocyanins are effective, widely available compounds that can be used in both the prevention and treatment of MetS and its complications. Increased consumption of anthocyanin-rich foods may contribute to the maintenance of normal body weight and modulation of the lipid profile in adults. However, further investigation is needed to confirm the beneficial effects of anthocyanins on serum glucose levels, improvement in insulin sensitivity and reduction in systolic and diastolic blood pressure.

Use of HPLC-MS to Determine the Loss of Metabolites in Apple Juices under Different Storage Conditions

The focus of this experiment was to compare the color and metabolic profile of apple juice from the red-fleshed cultivar 'Baya Marisa' with the white-fleshed cultivar 'Golden Delicious'. The changes in the phenolic compounds, organic acids, and sugar content during high-temperature short-time pasteurization and after one year of storage under different storage conditions were analyzed. A total of 26 individual phenolic compounds were identified and quantified. The total analyzed phenolics content (TAPC) decreased after pasteurization of the juices of both cultivars. The TAPC of fresh 'Baya Marisa' juice after pasteurization increased or remained the same compared to one-year stored 'Baya Marisa' juice, depending on the storage method. The sucrose content of the apple juice of both cultivars remained the same after pasteurization; interestingly, it decreased significantly after one year of storage, while the fructose and glucose content remained the same after pasteurization and increased significantly after one year of storage for both cultivars.

Black Queens of Fruits: Chemical Composition of Blackberry (Rubus subg. rubus Watson) and Black Currant (Ribes nigrum L.) Cultivars Selected in Serbia

Black fruits, especially blackberries and black currants, are highly appreciated by consumers due to their nutraceutical properties, which have reported health benefits. This study aimed to assess the fruit quality of the blackberry (cv. 'Čačanska Bestrna') and black currant (cv. 'Čačanska Crna') created at the Fruit Research Institute, Čačak (Republic of Serbia) by evaluating basic quality parameters (fruit weight, soluble solids), and content of primary (sugars and organic acids) and secondary (phenolic compounds) metabolites. Additionally, the study examined the quality of frozen and long-term frozen storage (6, 9, and 12 months). The results showed that 'Čačanska Crna' contained a high level of total soluble solids (15.23°Bx), sugars (93.06 mg g^-1), and a high index of sweetness (159.48) as well as a high content of acids (34.35 mg g^-1) in the fruit. Both species were found to contain forty-seven phenolic compounds, including phenolic acids, flavanols, and anthocyanins, analyzed using high performance liquid chromatography-mass spectrometry (HPLC-MS). 'Čačanska Bestrna' had the highest amounts of phenolic acids (66.85 mg 100 g^-1) and flavanols (53.99 mg 100 g^-1), whereas 'Čačanska Crna' showed the highest levels of flavonols (8.57 mg 100 g^-1) and anthocyanins (139.11 mg 100 g^-1). Furthermore, the study revealed that anthocyanins were the most abundant phenolic group in both blackberries and black currants, and their levels remained constant during frozen storage. The sugar content in both species remained unchanged, while the acid concentration increased over time in blackberries but remained consistent in black currants. Overall, the findings highlight the superior phenolic content, particularly anthocyanins, of the cultivars with black fruits selected in Serbia. These cultivars have great commercial potential for the fresh market and processing. Moreover, the study suggests that frozen storage is an effective method for preserving their quality and beneficial properties.

Advances in Postharvest Storage and Preservation Strategies for Pleurotus eryngii

The king oyster mushroom (Pleurotus eryngii) is a delicious edible mushroom that is highly prized for its unique flavor and excellent medicinal properties. Its enzymes, phenolic compounds and reactive oxygen species are the keys to its browning and aging and result in its loss of nutrition and flavor. However, there is a lack of reviews on the preservation of Pl. eryngii to summarize and compare different storage and preservation methods. This paper reviews postharvest preservation techniques, including physical and chemical methods, to better understand the mechanisms of browning and the storage effects of different preservation methods, extend the storage life of mushrooms and present future perspectives on technical aspects in the storage and preservation of Pl. eryngii. This will provide important research directions for the processing and product development of this mushroom.

Preservation of Biologically Active Compounds and Nutritional Potential of Quick-Frozen Berry Fruits of the Genus Rubus

Cryoprotective freezing methods are increasingly being developed and used as an effective means of protecting valuable bioactive compounds in processed berry fruits. The quick-freezing method allows the bioactive compounds in the plant material to be preserved over a longer period of time, thus providing a high-quality product with significant antioxidant capacity. The aim of this study was to determine the effects of the quick-freezing method on physico-chemical properties and bioactive compounds content of fruits in three soft fruit species: tayberry, raspberry, and blackberry, and to evaluate the stability of specific phytochemicals during the three-month storage period. The freezing method had a significant effect on the physicochemical properties with a significantly less drip loss observed after thawing in fruit frozen by quick-freezing (at −34 °C for 25 min) compared to fruit frozen classically (−18 °C to 24 h). The color of quick-frozen fruits also changed significantly less compared to fresh fruits. Of the bioactive compounds analyzed, it should be noted that there was a significantly lower loss of ascorbic acid recorded during quick-freezing. On average, the quick-frozen fruits contained 28% more ascorbic acid than the classical frozen fruits. In general, the quick-freezing procedure contributed to a better preservation of total polyphenolic compounds and anthocyanins, and thus berry fruits also showed higher values of antioxidant capacity during quick freezing than during the classical procedure. During the storage period of three months, a decrease in the content of all the bioactive compounds studied was observed, although it should be emphasized that this loss during storage was not as pronounced in fruits frozen by the quick-freezing method as in classically frozen fruits. It can be concluded that the quick-freezing contributes significantly to the preservation of valuable bioactive compounds of berries and that this processing method can be considered important for maintaining the nutritional properties of berry fruits.

Fruit Quality Characteristics and Biochemical Composition of Fully Ripe Blackberries Harvested at Different Times

We investigated how the quality of blackberry fruit changes during the ripening period. Since it is difficult to predict picking dates for blackberries, we were interested in how the quality of fully ripe fruit changed depending on the sampling date (from 28 July to 1 September). Blackberries (at full ripeness) were sampled at six weekly intervals and the contents of sugars, vitamin C, organic acids and phenolic components were analysed by high performance liquid chromatography combined with mass spectrometry. The colour parameters, total soluble solids and weight of the fruits were also measured. The results showed that the fruits at the last sampling had a significantly lower fruit weight and higher soluble solids. 'Cacanska Bestrna' had the highest fruit weight and vitamin C content (11.43 mg/100 g). The main sugars in blackberries were fructose (13.8-33.4 g/kg FW) and glucose (13.0-33.2 g/kg FW). 'Loch Ness' and 'Navaho' had a sweeter taste since they had the highest ratio of sugars and acids (S/A approx. 5.8) and 'Smoothstem' and 'Thornfree' had the sourest taste, with a ratio of S/A 2.5. Blackberries harvested at the first two samplings had lower anthocyanin contents than fruits from later sampling times. There were no significant differences in the content of flavonols, ellagitannins, flavanols or hydroxycinnamic acids during the ripening period. The content of vitamin C in the fruits did not change among samplings, but the fruits had a higher content of organic acids at the first two or three samplings. The results may be useful for both the processing industry and growers to set quality standards for each variety and to determine the optimal harvest time.

Examining the Performance of Two Extraction Solvent Systems on Phenolic Constituents from U.S. Southeastern Blackberries

Two common extraction solvent systems, namely acidified aqueous methanol and acidified aqueous acetone, were used to extract blackberry phenolics, and the antioxidant properties of the recovered extracts were compared. The crude extracts were fractionated into low- and high-molecular-weight phenolics by Sephadex LH-20 column chromatography. The hydrophilic-oxygen radical absorbance capacity (H-ORAC_FL), ferric reducing antioxidant power (FRAP), and the cellular antioxidant activity (CAA) assays were employed as indices to assess antioxidant capacity of the extracts and their respective fractions. The methanolic solvent system displayed a greater efficiency at extracting anthocyanin and flavonol constituents from the blackberries, while the acetonic solvent system was better at extracting flavan-3-ols and tannins. Anthocyanins were the dominant phenolic class found in the blackberries with 138.7 ± 9.8 mg C3G eq./100 g f.w. when using methanol as the extractant and 114.6 ± 3.4 mg C3G eq./100 g f.w. when using acetone. In terms of overall antioxidant capacity of blackberry phenolics, the acetonic solvent system was superior. Though present only as a small percentage of the total phenolics in each crude extract, the flavan-3-ols (42.37 ± 2.44 and 51.44 ± 3.15 mg/100 g f.w. in MLF and ALF, respectively) and ellagitannins (5.15 ± 0.78 and 9.31 ± 0.63 mg/100 g f.w. in MHF and AHF, respectively) appear to account for the differences in the observed antioxidant activity between the two solvent systems.

A Red-Berry Mixture as a Nutraceutical: Detailed Composition and Neuronal Protective Effect

Recommendations towards increased consumption of fresh fruit and vegetables are well supported by epidemiological and clinical trials. However, in some specific cases, it is difficult to follow these recommendations and the use of nutraceuticals or, in the present work, a freeze-dried fruits mixture can be recommended in order to afford the optimal consumption of dietary polyphenols naturally present in fruits and vegetables. In this work we have carefully characterized a red-berry mixture in terms of polyphenol composition, encountering mainly anthocyanins, which account for a total of 2.8 mg/g as cyanidin-3-glucoside equivalents. Additionally, we have assayed the red-berry blend in a cell model of neurological damage by differentiating the cells and measuring the effect of red-berry polyphenols on cell viability and redox state by flow cytometry. The berry-fruit extract showed an inhibitory effect on differentiated SH-SY5Y ROS formation at a concentration as low as 250 µg/mL (33% inhibition). The results show the potential of this berry-fruit blend for its nutraceutical use in the prevention of the neurodegeneration associated with age or environmental agents.

Effect of Processing and Storage on the Quality of Beetroot and Apple Mixed Juice

In recent years, there has been a growing interest in the development of health-promoting and disease-preventing functional foods. Beetroot is a promising vegetable because of its outstanding antioxidant activity, vivid colour, and content of bioactive compounds. In the present study, the quality of pure beetroot and apple juices as well as that of their mixture was evaluated by measuring changes of colour, betalain content, and antioxidant activity during processing and storage. No perceivable colour changes of the beetroot juice were observed after adding apple juice up to 85% of the total amount. However, the antioxidant activity was proportionally reduced with the addition of apple juice. Pasteurization negatively affected the content of betalains but did not influence the antioxidant activity. Storage led to colour modifications and reduction of betalains and antioxidant activity. Through preliminary shelf-life studies, a durability of 65 days at room temperature for apple and beetroot juice blends was calculated. The novelty of this study lies in an extended description of physico-chemical characteristics of a fresh apple and beetroot blended juice obtained from local products, in the study of the effects of processing and storage on its quality, and in the estimation of its shelf-life after storage at different temperatures.

Characterization of the nutrient profile of processed red raspberries for use in nutrition labeling and promoting healthy food choices

BACKGROUND:

Red raspberries (Rubus idaeus L.) contain varied nutrients and phytochemicals important for healthy aging. Processing berries extends their shelf-life and culinary applications, although information on nutritional content among processed forms are limited.

OBJECTIVE:

The main objective of the project was to conduct a market basket study to characterize nutrient content and variation in processed red raspberry (RRB) products (i.e., individually quick frozen (IQF), purée, concentrates). Secondary objectives were to provide new data to the USDA nutrient composition database on processed RRB, which is now complete, and to evaluate RRB forms relative to regulatory (US FDA) criteria for food labeling based on Dietary Reference Intake (DRI) recommendations expressed as % Daily Values (DV).

METHODS:

Processed raspberry product samples were obtained in 2017 from retail outlets, processing plants and distributors, in and outside the USA. Samples were analyzed by pre-qualified laboratories using pre-approved AOAC methods and validated HPLC methods.

RESULTS:

Nutrient variance in domestic compared to imported product was observed, but on average IQF and purée with seeds are excellent sources of dietary fiber based on FDA criteria of providing ≥20% DV, IQF and purée are good (10–19% DV) sources of copper, thiamin, riboflavin and folate, and all forms were excellent or good sources of vitamin C and manganese. IQF and puréed red raspberries may also be considered a valuable fruit source of lutein/zeaxanthin.

CONCLUSIONS:

Processed RRB are nutrient rich options for including in a diet for healthy aging.

Jabuticaba (Myrciaria jaboticaba) juice obtained by steam-extraction: phenolic compound profile, antioxidant capacity, microbiological stability, and sensory acceptability

Jabuticaba (Myrciaria jaboticaba) is a dark-colored fruit native to Brazil that has a desirable flavor and high anthocyanin content. In the present study, jabuticaba juice was produced by steam-extraction and the phenolic compound profile, antioxidant capacity, instrumental color, and microbiological quality were evaluated during 90 days of storage at 25 °C. Cyanidin-3-O-glucoside represented 45% of the total phenolic content of the juice, which reduced with extent of 80% during storage. Total phenolic content of the juice increased by 59% during 90 days of storage, which entailed, average 4.4-fold increase in the content of gallic and ellagic acids. FRAP assay was most sensitive for measuring gallic and ellagic acids, while the TEAC assay was the most sensitive for measuring anthocyanins. Although [Formula: see text] and [Formula: see text] values of jabuticaba juice decreased and [Formula: see text] increased during storage. Jabuticaba juice remained microbiologically stable during storage, and did not support the growth of inoculated Escherichia coli and Salmonella enteritidis, suggesting antimicrobial activity.

Fast and Simple Discriminative Analysis of Anthocyanins-Containing Berries Using LC/MS Spectral Data

INTRODUCTION

Anthocyanins are potent antioxidant agents that protect against many degenerative diseases; however, they are unstable because they are vulnerable to external stimuli including temperature, pH and light. This vulnerability hinders the quality control of anthocyanin-containing berries using classical high-performance liquid chromatography (HPLC) analytical methodologies based on UV or MS chromatograms.

OBJECTIVE

To develop an alternative approach for the quality assessment and discrimination of anthocyanin-containing berries, we used MS spectral data acquired in a short analytical time rather than UV or MS chromatograms.

METHOD

Mixtures of anthocyanins were separated from other components in a short gradient time (5 min) due to their higher polarity, and the representative MS spectrum was acquired from the MS chromatogram corresponding to the mixture of anthocyanins.

RESULTS

The chemometric data from the representative MS spectra contained reliable information for the identification and relative quantification of anthocyanins in berries with good precision and accuracy.

CONCLUSION

This fast and simple methodology, which consists of a simple sample preparation method and short gradient analysis, could be applied to reliably discriminate the species and geographical origins of different anthocyanin-containing berries. These features make the technique useful for the food industry. Copyright © 2017 John Wiley & Sons, Ltd.

Do optimally ripe blackberries contain the highest levels of metabolites?

Five blackberry cultivars were selected for the study ('Chester Thornless', 'Cacanska Bestrna', 'Loch Ness', 'Smoothstem' and 'Thornfree') and harvested at three different maturity stages (under-, optimal- and over-ripe). Optimally ripe and over-ripe blackberries contained significantly higher levels of total sugars compared to under-ripe fruit. 'Loch Ness' cultivar was characterized by 2.2-2.6-fold higher levels of total sugars than other cultivars and consequently, the highest sugar/acids ratio. 'Chester Thornless' stands out as the cultivar with the highest level of vitamin C in under-ripe (125.87mgkg(-1)) and optimally mature fruit (127.66mgkg(-1)). Maturity stage significantly affected the accumulation of phenolic compounds. The content of total anthocyanins increased for 43% at optimal maturity stage and cinnamic acid derivatives for 57% compared to under-ripe fruit. Over-ripe blackberries were distinguished by the highest content of total phenolics (1251-2115mg GAE kg(-1) FW) and greatest FRAP values (25.9-43.2mM TE kg(-1) FW).

Aspectos físico-químicos e microbiológicos de polpas de frutas comercializadas em Petrolina (PE) e Juazeiro (BA)

Resumo Objetivou-se com este trabalho avaliar as características físico-químicas e microbiológicas de polpas de frutas congeladas comercializadas em Petrolina (PE) e Juazeiro (BA). Para tanto, foram analisados sete sabores de quatro marcas de polpas de frutas (A, B, C e D) quanto ao número total de bolores e leveduras, coliformes totais e termotolerantes a 45 °C (fecais), pH, sólidos solúveis e cor. Os resultados obtidos para um mesmo sabor, das diferentes marcas, de quatro repetições, foram submetidos à análise de variância e comparação de médias pelo teste de Tukey, a 5% de significância. Os resultados de cada amostra foram comparados, individualmente, aos valores determinados pela legislação brasileira para cada sabor de polpa de fruta. Todas as marcas apresentaram características de sólidos solúveis e cor condizentes com a legislação, com pequenas variações entre marcas, a depender do sabor. A marca C apresentou amostras com valores elevados de bolores e leveduras em todos os sabores. Observou-se, ainda, valores de pH diferentes do estabelecido pela legislação nas polpas de manga e caju. Também foram detectados coliformes termotolerantes em polpas da marca C. Concluiu-se que 61,75% das polpas da marca C, 14,29% das polpas da marca A e 14,29% das polpas da marca D apresentaram-se impróprias para o consumo. Constatou-se também a necessidade de se estabelecerem, na legislação, padrões físico-químicos para polpas de abacaxi e tamarindo.

Impact of Frozen Storage on the Anthocyanin and Polyphenol Contents of American Elderberry Fruit Juice

The effects of frozen storage on the anthocyanin and polyphenol content of elderberry fruit juice are investigated. Juice from three genotypes of American elderberry (Adams II, Bob Gordon, and Wyldewood) was screened for total phenolic (TP) and total monomeric anthocyanin (TMA) contents with spectrophotometric methods. The individual anthocyanin content (IAC) of the juice was tested by coupling solid phase extraction with ultraperformance liquid chromatography-tandem mass spectrometry. Juice samples were tested initially upon harvest and then again after 3, 6, and 9 months of frozen storage. Juice from the three different genotypes had significantly different TP, TMA, and IAC profiles initially (p < 0.05). The TP, TMA, and IAC contents of the juice from different genotypes were significantly affected (p < 0.05) by the frozen storage time, suggesting that both genotype and length of frozen storage time can affect the anthocyanin content of elderberry fruit juice.

Frost decreases content of sugars, ascorbic acid and some quercetin glycosides but stimulates selected carotenes in Rosa canina hips

Primary and secondary metabolites of Rosa canina hips were determined by HPLC/MS during ripening and after frost damage. Rose hips were harvested six times from the beginning of September until the beginning of December. Color parameters a*, b* and L* decreased during maturation. Glucose and fructose were the predominant sugars representing up to 92% total sugars, and citric acid was the major organic acid detected in rose hips (constituting up to 58% total organic acids). Total sugar and ascorbic acid content significantly decreased after frost damage; from 42.2 to 25.9 g 100 g(-1) DW for sugars and from 716.8 to 176.0 mg 100 g(-1) DW for ascorbic acid. Conversely, β-carotene and lycopene levels increased in frostbitten rose hips to 22.1 and 113.2 mg 100 g(-1) DW, respectively. In addition to cyanidin-3-glucoside (highest level in hips was 125.7 μg 100 g (-1) DW), 45 different phenolic compounds have been identified. The most abundant were proanthocyanidins (their levels amounted up to 90% of total flavanol content) and their content showed no significant differences during maturation. The levels of catechin, phloridzin, flavanones and several quercetin glycosides were highest on the first three sampling dates and decreased after frost. Antioxidant capacity similarly decreased in frostbitten rose hips. Total phenolic content increased until the third sampling and decreased on later samplings.

Nutrients responses of Pleurotus ostreatus to slow frozen storage in the short term

This paper improves the understanding of changes happening with nutraceuticals in slow freezingPleurotus ostreatusduring short-term storage.