Effects of red raspberry polyphenols and metabolites on biomarkers of inflammation and insulin resistance in type 2 diabetes: A pilot study

Berry fruits are rich in polyphenolic compounds (PCs) and may promote health benefits. Anthocyanin (ACNs) concentrations of red raspberry (RR)(Rubus idaeus) extracts were 887.6 ± 262.8 μg/g consisting mainly of...

Recent Studies on Berry Bioactives and Their Health-Promoting Roles

Along with the increased knowledge about the positive health effects of food bioactives, the eating habits of many individuals have changed to obtain higher nutritional benefits from foods. Fruits are among the most preferred food materials in this regard. In particular, berry fruits are important sources in the diet in terms of their high nutritional content including vitamins, minerals, and phenolic compounds. Berry fruits have remedial effects on several diseases and these health-promoting impacts are associated with their phenolic compounds which may vary depending on the type and variety of the fruit coupled with other factors including climate, agricultural conditions, etc. Most of the berries have outstanding beneficial roles in many body systems of humans such as gastrointestinal, cardiovascular, immune, and nervous systems. Furthermore, they are effective on some metabolic disorders and several types of cancer. In this review, the health-promoting effects of bioactive compounds in berry fruits are presented and the most recent in vivo, in vitro, and clinical studies are discussed from a food science and nutrition point of view.

Changes in the Polyphenol Content of Red Raspberry Fruits during Ripening

Berry fruits that contain large amounts of polyphenol compounds are expected to exhibit health and anti-aging effects due to the antioxidant activities of these components. Among the various polyphenols, flavan-3-ol derivatives are known to have a particularly high functionality. In this study, the maturity of red raspberry fruits is classified into eight stages based on the polyphenol content at each stage. Quantification of the various compounds and investigation of the DPPH and ABTS radical scavenging activities were carried out. The total polyphenol content, including that of the flavan-3-ol derivatives, was the highest in immature fruits, gradually decreasing during fruit maturation, during which the radical scavenging activity also decreased. Based on our quantitative results, it was considered that the decrease in the flavan-3-ol derivative content due to fruit ripening was largely related to the increase in the amount of anthocyanin derivatives. Considering that the decreased contents of these compounds were related to the expression levels of polyphenol biosynthetic enzymes, quantification was performed using the semi-quantitative polymerase chain reaction, but the only change observed was the increased expression of the enzyme that synthesizes anthocyanins during maturation. Therefore, it was suggested that it is necessary to inhibit anthocyanin synthesis to increase the contents of highly functional flavan-3-ol derivatives in the mature fruit.

Recent advances in metabolomic analyses of berry fruits and their in vivo metabolites

Metabolomics, one of the most recent additions to the systems biology toolkit, has been used to study the metabolism and physiology of living organisms. In the field of food research, metabolomics has lately gained popularity as a technique for determining the quality, processing, and safety of raw materials and final food products, as well as for identifying biomarkers linked to food intake and disease. This review aimed to provide an overview of the current understanding of the analytical techniques used for metabolomics and their application to berries with a special emphasis on the in vivo studies. Specifically, identification of biomarkers of biological activity and in vivo metabolites of berries using metabolomics approach is covered.

Physico-chemical Properties, Mineral Matter, Organic Acid, Amino Acid, and Plant Hormones Content of Goji Berry (Lycium barbarum L.) Grown in Turkey

With high nutritional value, goji berry is an important fruit for human nutrition and health. Goji berry cultivation is done widely in many countries, farming has become widespread in recent years in Turkey. In study grown goji berry (Lycium barbarum L.) in Turkey are determined the physical and chemical characteristics of fruit (pH, titration acidity, dry matter content, ash content, water activity (aw) value, protein content, HMF content, total phenolic content, total sugar content, reducing sugar content, sucrose content, colour values, mineral contents, organic acid contents, amino acid contents and some plant hormone content). Goji berry fruits have pH value 5.18, titration acidity value 2.16%, dry matter content 89.40%, ash content 4.30%, water activity (aw) value 0.35, protein content 13.18%, HMF content 9.38 mg/kg, total phenolic content 9.05 mg GAE/g, total sugar content 59.26%, decreasing sugar content 57.35%, sucrose content 1.90%, L* value 40.33, a* value 22.97, b* value 33.00, C* value 40.21, H° value 55.15. In addition, the mineral content, organic acid content, amino acid content and some plant hormones of goji berry fruits were determined by analysis.

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.

The Kinetics of Two-Step Ellagitannin Extraction from the By-products of Selected Processed Fruits of the family Rosaceae

The paper presents the kinetics of two-step ellagitannin (ET) extraction with an aqueous acetone solution from two technological types of pomace from selected berry fruits of the Rosaceae family. ETs were identified and quantified using HPLC–MS and HPLC–DAD. The results revealed the extraction kinetics of total ETs, their high and low molecular weight fractions (≤ 1569 Da and > 1569 Da), and individual ETs characteristic of the examined fruits. ET extraction proceeded at a faster rate in the first step, regardless of the tested pomace. For all pomace variants, the mean extraction half time t1/2 was 48 min in the first step and 70 min in the second step. The fruit species and the technological type of pomace were not found to exert a definite effect on the kinetics of ET extraction. Statistical analysis demonstrated that the molecular weight of ETs did not influence the kinetics of their extraction, either. It was shown that the technological type of pomace had a significant impact on the extraction rate of both low molecular weight (LMW) and high molecular weight (HMW) ETs in the first extraction step, with the mean t1/2 being 44 min for pomace from juice production and 63 min for pomace from puree production.

No Clinical Symptom Experienced after Consumption of Berry Fruits with Positive RT-qPCR Signals of Human Norovirus

Human noroviruses (hNoVs) are the most important foodborne viruses, and soft berries are one of the most common food sources of hNoV outbreaks and contamination. This paper presents a human volunteer study in order to investigate the correlation between molecular detection results of hNoV in berries with the public health risks. The participants with diverse histo-blood group antigens (HBGAs) phenotypes were required to consume self-purchased berries and meanwhile submit aliquots of the products for reverse transcription-quantitative polymerase chain reaction (RT-qPCR) detection. As a result, none of the 20 participants reported any hNoV infection-like symptoms after six independent consumptions (120 consumptions in total). In contrast, within the 68 berry samples with >1% virus recoveries, 28 samples were detected to be positive for hNoV GI and/or GII (the positive rate at 41%). All of the positive signals were below the limit of quantification (<120 genome copies/g) except one fresh strawberry sample at 252 genome copies/g. It is expected that this study would contribute to the definition of quantitative standards for risk assessment purposes in the future.