Journal of Berry Research - Volume 7, issue 4

Authors: Kiheri, Heikki | Heinonsalo, Jussi | Timonen, Sari

Article Type: Research Article

Abstract: BACKGROUND: Visualization of ericoid mycorrhizal colonization using traditional methods relies on either fresh or KOH stored samples. Increasing interest in studying ericoid mycorrhization has highlighted a need for methods which can be used for preserved samples and are simple to implement with commonly available equipment. OBJECTIVE: The aim of this study was to improve on traditional techniques for staining ericoid mycorrhizal fungi and microscopically visualizing ericoid mycorrhizal roots which have been preserved. METHODS: Ericoid mycorrhizal roots were placed in KOH or frozen at –20 °C for long-term storage. Traditional Trypan Blue staining methods were modified to …reduce damage to fine mycorrhizal hyphae and cortical cells. A high light-intensity dark-field microscopy technique was applied to clearly visualize stained mycorrhizae. The novel application was compared to other commonly used practices. RESULTS: Trypan Blue staining without KOH storage or clearing allowed for successful staining of ericoid mycorrhizal roots stored at –20 °C. The application of high light-intensity dark-field microscopy provided high contrast visualization of mycorrhizal structures. CONCLUSIONS: The modified Trypan Blue staining method was effective on frozen root samples, with dark-field microscopy being particularly effective at visualizing dark colored roots. Advantages to this method are low cost and relatively fast application time. Therefore, this method is a realistic option for large scale analyses with many samples which require long-term preservation. Show more

Keywords: Ericoid, mycorrhizae, dark-field microscopy, Trypan Blue staining, mycorrhizal colonization

DOI: 10.3233/JBR-170160

Citation: Journal of Berry Research, vol. 7, no. 4, pp. 231-237, 2017

Authors: Sosa-Morales, M.E. | Flores-López, T. | Miranda-Estrada, D.E. | Kaur Kataria, T. | Abraham-Juárez, M. del R. | Cerón-García, A. | Corona-Chávez, A. | Olvera-Cervantes, J.L. | Rojas-Laguna, R.

Article Type: Research Article

Abstract: BACKGROUND: Dielectric properties (DPs) are relevant parameters for microwave applications, such as sensors and heating for drying, mold control or disinfestation. DPs of berries are necessary in order to develop processes involving microwaves, reported with high potential for berries preservation. OBJECTIVE: To analyze the DPs in the microwave range and physicochemical properties of raspberry, strawberry and blackberry. METHODS: DPs were measured from 0.5 to 25 GHz at 20, 40 and 60°C using the open-ended coaxial probe method. Several physicochemical properties and biocompounds contents were determined. RESULTS: Dielectric constant increased with increasing temperature, and decreasing with …increasing frequency. Loss factor decreased with increasing temperature, and from 1.5 to 25 GHz, losses increased with increasing frequency. All berries had similar DP values, and microwaves had deeper penetration into strawberry (3.5 cm) than blackberry and raspberry samples (2.7 cm). CONCLUSIONS: Dielectric properties values are useful for further applications of microwaves for these berries, such as sensing, disinfestation, avoiding decay or drying. Show more

Keywords: Dielectric properties, berries, penetration depth

DOI: 10.3233/JBR-170161

Citation: Journal of Berry Research, vol. 7, no. 4, pp. 239-247, 2017

Authors: Ivanišová, Eva | Grygorieva, Olga | Abrahamová, Vlasta | Schubertova, Zuzana | Terentjeva, Margarita | Brindza, Ján

Article Type: Research Article

Abstract: BACKGROUND: A diet rich in fruits and fruit-based products could improve human health. Jujube fruit is getting popularized in the world due to the high content of vitamin C, phenolic, flavonoids, polysaccharides and natural colorant properties. OBJECTIVES: The objective of this study was to evaluate the morphological and biological properties (antioxidant activity, total polyphenol, flavonoid and carotenoid content) of 15 genotypes of dry jujube fruit from Nova Kachovka (Ukraine). MATERIALS AND METHODS: Morphological characteristics (weight, width, and length), antioxidant activity by two different methods (DPPH, molybdenum reducing antioxidant power) and content of total polyphenols, flavonoids and …carotenoids were analyzed in jujube fruit. RESULTS: The average weight of jujube fruit ranged from 2.52 to 19.37 g, width from 16.66 to 35.60 mm and length from 18.11 to 40.69 mm. Total polyphenol content ranged from 8.76 to 21.61 mg GAE per g, total flavonoid content from 1.49 to 11.57 μg QE per g and total carotenoid content from 1.53 to 14.31 μg per g. All tested samples exhibited DPPH• radical scavenging activities with values from 11.18 to 16.82 mg TEAC per g. Antioxidant activity by molybdenum reducing antioxidant power method ranged from 209.64 to 481.55 mg TEAC per g of dry matter. Differences between the genotypes were significant in all observed parameters. CONCLUSION: The results showed that the jujube fruit is rich in bioactive compounds and can be used in food, medicine and pharmacy industry. Show more

Keywords: Fruit, genotypes, antioxidant, carotenoids, polyphenols, flavonoids

DOI: 10.3233/JBR-170162

Citation: Journal of Berry Research, vol. 7, no. 4, pp. 249-260, 2017

Authors: Sette, Paula | Franceschinis, Lorena | Schebor, Carolina | Salvatori, Daniela

Article Type: Research Article

Abstract: BACKGROUND: Raspberry is a very popular berry, with a short postharvest life. Drying was proposed for obtaining different raspberry-based products. When rehydration is needed for foods direct consumption or use in composite products, a comprehensive understanding of the rehydration characteristics and quality attributes changes is necessary for a proper selection of processing. OBJECTIVE: The aim of the present work was to analyze the evolution of anthocyanin pigments and several physical properties upon rehydration of dried raspberries. METHODS: Raspberries were dehydrated (air- and freeze-drying) with sugar infusion pretreatments, and then rehydrated at different temperatures. Rehydration kinetics and …several quality parameters were analyzed. RESULTS: Pretreated dried samples showed a significantly reduced rehydratability, and preserved dried fruit firmness. Upon rehydration, anthocyanins retention range was 8–42% in control raspberries and 40–90% in pretreated samples. Freeze-dried fruits showed a rapid water uptake but could not restore the water lost upon drying. These samples exhibited a high retention of anthocyanins and color, and a soft texture. When raisin-like fruits are required, samples with pretreatments and further drying should be selected, since they better maintained texture characteristics during a short period of consumption (5–20 min); however, the anthocyanin content was lower than that for control samples. Both freeze- and air-dried control samples preserved the red hues, while maintaining the luminosity during rehydration. CONCLUSIONS: The evaluation of quality parameters of rehydrated raspberries, such as color, anthocyanin content, texture and volume, as well as the rehydration indices appeared to be useful to select the best drying and rehydration conditions. Show more

Keywords: Raspberry, drying, freeze-drying, rehydration capacity, anthocyanins, physical properties

DOI: 10.3233/JBR-170163

Citation: Journal of Berry Research, vol. 7, no. 4, pp. 261-280, 2017

Authors: Bridges, David F. | Breard, Anna | Lacombe, Alison | Valentine, Don C. | Tadepalli, Shravani | Wu, Vivian C.H.

Article Type: Research Article

Abstract: INTRODUCTION: Human noroviruses (HuNoVs) are among the leading causes of foodborne illness worldwide and current treatments are ineffective at reducing spread and severity of infection. Previous studies have demonstrated the antimicrobial properties of lowbush blueberries, but little work has been done investigating antiviral properties of blueberries. OBJECTIVE: The objective of this study was to determine the antiviral effects of lowbush blueberry fractional components against Tulane Virus in a tissue culture system. METHODS: Dried lowbush blueberry powder was separated into five fractional components and LLC-MK2 cells were treated with dilutions of each fraction during virus inoculation to …determine if fraction exposure reduced subsequent virus replication. RESULTS: Total blueberry extract (F1) exposure resulted in viable particle reduction to undetectable levels (>4.95 log PFU/ml) followed by anthocyanins plus proanthocyanidins (F3; 4.14±0.83 log PFU/ml), monomeric phenolics (F2; 2.90±0.09 log PFU/ml), anthocyanins (F4; 2.27±0.29 log PFU/ml), and proanthocyanidins (F5; 1.73±0.25 log PFU/ml) at a 1 : 2 dilution of each fraction. CONCLUSION: The significant reduction of TV caused by blueberry fraction exposure, in combination with no noted signs of cytotoxicity, indicates promising use of blueberry extract antiviral treatment. Show more

Keywords: Tulane virus, lowbush blueberries, phenolics, anthocyanins, proanthocyanidins

DOI: 10.3233/JBR-170164

Citation: Journal of Berry Research, vol. 7, no. 4, pp. 281-289, 2017

Authors: Dolkar, Phuntsog | Dolkar, Diskit | Kant, Anil | Chaurasia, O.P. | Stobdan, Tsering

Article Type: Research Article

Abstract: BACKGROUND: In dioecious species the morphological and physiological adjustment to cold and freezing conditions may differ significantly between male and female individuals due to greater reproductive effort by females. OBJECTIVES: To assess the importance of gender-specific responses of H. rhamnoides of cold acclimation and freeze tolerance in trans-Himalayan environments. METHOD: We measured the proline contents in leaves and shoots in male and female H. rhamnoides from mid August to mid December in standing crop. RESULTS: Proline content in leaves showed a significant increasing trend from August to October followed by a steady …decline from November onwards in both the genders. Progression in season from August to December is related linearly to the increase in proline contents in both male (R 2  = 0.967) and female (R 2  = 0.926) shoots. Increase in altitude (3202–3812 m amsl) of plant origin is related linearly to increase in proline contents in both male (R 2  = 0.676) and female (R 2  = 0.858) shoots. The overall proline contents in both leaves and shoots were significantly higher in male (112±77, 143±66μ M g-1 , respectively) than in female (87±46, 119±82μ M g-1 , respectively). CONCLUSION: The study suggested sexually dissimilar responses to cold and freezing conditions in H. rhamnoides and that male possess a better self protection mechanism than female. Leaves developed tolerance against cold stress more quickly than shoots. Show more

Keywords: Abiotic stress, acclimation, chilling, climate change, himalaya, proline

DOI: 10.3233/JBR-170165

Citation: Journal of Berry Research, vol. 7, no. 4, pp. 291-297, 2017