Simultaneous determination of flavonols and phenolic acids by HPLCCoulArray in berries common in the Nordic diet

Ensieh Hajazimi (a), Rikard Landberg( a, b), Galia Zamaratskaia (a), Food Science and Technology 74 (2016) 128e134

(a) Department of Food Science, Uppsala BioCenter, Swedish University of Agricultural Sciences, Uppsala, Sweden  (b) Unit of Nutritional Epidemiology, Institute of Environmental Medicine, Karolinska Insitutet, Stockholm, Sweden

This paper is a methods study testing a new method of detecting antioxidants in wild berries. Although the method information is interesting, of importance to us berry people is the verification that northern berries are endowed with very high levels of antioxidants, in this case flavonols and phenolic compounds even when the berries were  commercially store bought and frozen. Sea buckthorn (Hippophae rhamnoides)  topped the charts of highest flavonols, hydrobenzoic and hydrocinnamic acid compounds with lingonberry (Vaccinium vitas-idaea) and bilberry (V. myrtillus) not far behind. The cloudberry (Rubus chamaemorus)  had less than half total phenolics of the other berries.  The phenolic compound found in greatest concentration in sea buckthorn was Isorhamnetin; in lingonberry,  quercetin; in bilberry – myricetin; and finally in cloudberry – gallic acid.

berry phenolocs

 

Wouldn’t it be great if these berries were available frozen in Alaska stores? For now, enjoy berry picking or purchasing fruit at your local farmers market in summer. The health benefits can be great (although you have to eat twice as many cloudberries as the other fruit)!

Using traditional ecological knowledge to understand and adapt to climate and biodiversity change on the Pacific Coast of North America

2019. Victoria Rawn Wyllie de Echeverria , Thomas F. Thornton  Ambio https://doi.org/10.1007/s13280-019-01218-6

2019. Wyllie de Echeverria, Thornton

The authors tackle one of the most complex issues in climate change science and ecology – how to include a human element in identifying change including traditional knowledge of plants and animals. How can human experiences, languages and traditions be used to verify change, and how can the importance of these traditions be included in ecological studies of climate change.  One main goal, of course,  is to identify ways indigenous people can maintain customary uses of their region, in this case, coastal areas in Southeast Alaska, while adapting to broader ecological changes that occur in an ecosystem.  Participants in a survey noted weather pattern shifts in their lifetime such as more snow, more rainfall, as well as shifts in the seasons. The researchers also examined language patterns to learn about traditional words used for weather or activities related to weather such as “foods being dried in the sun”. They indicated that changes in plant use in the region was most likely because of land use changes (logging, land development) rather than specific climate change.

One case study examined changes to salmonberry and blueberry species that are considered keystone species because they are used heavily by locals and have a long tradition of use. The authors tried to make connections between people’s recollections, historical knowledge and current practices compared to ecological knowledge of berry picking sites, yields, berry quality and more. I think back to some of the experiments in ecology I have been involved with over the years. They are so complex, it is difficult to isolate a single or even a handful of biological causes for a particular observation. For instance, there are so many reasons why berries might not appear in a season (frost during spring, drought, too much rain, poor soil nutrition, predation, and on and on. Recollections might be due to any or a combination of these factors. Attributing them to climate change is tricky and challenging. Human knowledge might just add to the evidence, but as climate scientists will agree, it takes many, many years and a lot of data points to begin to draw conclusions.

 

Getting ready for wild blueberries!

This recipe is sure to get you drooling for fresh berry scones. I made them with wild blueberries, and then tried lingonberries– both are great. Also try substituting buttermilk for the heavy cream. Yum!

Blueberry scones

 

 

How Many Bee Visits Give Good Fruit Set in Red Raspberries?

Two Prolonged Bee Visits Suffice to Maximize Drupelet Set for Red Raspberry by Corey J. Andrikopoulos and James H. Cane, Utah State University, Logan, HORTSCIENCE 53(10):1404–1406. 2018. https://doi.org/10.21273/HORTSCI13124-18

Everyone knows that insect pollination is critical for fruit set in many commercial berry species. The red raspberry is no exception. It produces an aggregate fruit composed of individual drupelet fruits. If the weather is bad, the insects are not flying, or something else interrupts pollination, you can easily get misshapen fruit and lower yields. Researchers at Utah State found that it only takes two prolonged visits of 1 minute or more to get great fruit set. You don’t need hundreds of bees visiting the flowers. Here are a few tidbits about red raspberries from this article:

  1. Red raspberries are mostly self fertile but because the pollen bearing anthers are not located directly adjacent to the female stigmas, self pollination can be spotty.
  2. A single flower bears 60 – 90  stamens with ample pollen, but bees and other insects are needed to move the pollen to the central region of female stigmas. Each individual stigma needs to be pollinated to get a good fruit.
  3. Previously scientists estimated that up to 68 visits per flower were necessary to get adequate fruit set, but these authors showed that 2 visits were great.
  4. For two visits to be adequate, the bee must really work the flower for a prolonged period of time (up to a minute or more). Bees often spend long times on a newly opened flower first thing in the morning because that’s when nectar flow is at its peak after a night time of storing up nectar in the flower’s nectar pool.
  5. Individual flowers remain receptive for about 2 days, and every morning the nectar pool is recharged. Nectar release is temperature dependent.
  6. By individually covering flowers as they bloomed and comparing them to uncovered controls, the researchers showed that bee visits increased drupelet formation by 2 to 4 times. If a flower was visited first thing in the day for a prolonged period, two such visits would be sufficient to have great fruit formation.
  7. There is also a condition of over visitation where bees actually damage the female stigmas if there are too many of them working the flowers.

Adding honey bee hives to a raspberry garden is a good idea for most commercial businesses. However, Alaska temperatures, especially in the a.m. can be cold – too cold for honey bees to be very active. Since nectar flow is greatest first thing in the morning, wild bumble bees become even more critical for great fruit set in northern gardens.

 

 

Fruit and Vegetable Waste That is Not Really Waste

Fruit and Vegetable Waste: Bioactive Compounds, Their Extraction, and Possible Utilization  Narashans Alok Sagar, Sunil Pareek, Sunil Sharma, Elhadi M. Yahia , and Maria Gloria Lobo 2018. Comprehensive reviews in Food Science and Food Safety Vol 00. Available online: https://www.researchgate.net/publication/324170873_Fruit_and_Vegetable_Waste_Bioactive_Compounds_Their_Extraction_and_Possible_Utilization

Years ago when I was completing my PhD on lingonberries I learned quite a lot about fruit processing how even the steam created in the process of making lingonberry sauce was captured and “mined” for a whole host of volatile and aromatic compounds that were packaged and sold for use somewhere else in the food industry. This article is a fascinating review of even more modern techniques being used to extract bioactive compounds from what would otherwise be called food waste.  After the apple has been peeled and sliced, there is a tremendous waste stream that includes stems, peels, seeds and pulp that usually ends up in a compost pile or worse- buried in a landfill. “.. Apples generate 10.91% of seed and pulp as by-products, and 89.09% of final products during slicing.”  When you think about the tons of apple products made worldwide, that’s a lot of waste from a single fruit! Bananas yield 35% waste through their peel!

“Losses and waste occur during all phases of the supply and handling chain, including during harvesting, transport to packinghouses or markets, classification and grading, storage, marketing, processing, and at home before or after preparation. Losses occur throughout the supply chain from production throughout all postharvest stages before consumption.”

Although this article emphasizes tropical fruits, it is an eye opener as far as what is actually left behind after processing, and the technology being used to capture such things as dietary fiber, phenolic compounds, flavorings, aromas and more. Most fascinating is a list of fruits that are treated with microorganisms to release a whole rainbow of enzymes, organic acids, and proteins that are then packaged and used in other food products as stabilizers, agents to prevent browning in processed products. We often look at the food industry in a poor light, but food chemistry is far more complex than most people realize, and this is a great example of recycling and repurposing that has been happening for many years.

The article also describes methods by which this waste extraction happens. Such exotic processes as microwave-assisted extraction, pulsed electrical field extraction, enzyme assisted and liquid to liquid extraction seem so foreign but are part of a growing technology to harvest everything of value from the waste stream and make it useful. Pretty impressive! Of course, you could eat the entire apple- peels, seeds and all, but even that would not provide the valuable components liberated by the many extraction techniques.

 

Optimum nutrient levels in soils and leaves of haskap, Lonicera caerulea

DETERMINATION OF SOIL AND PLANT NUTRIENT SUFFICIENCY LEVELS FOR HASKAP (LONICERA CAERULEA L.). 2018. Ekene Mark-Anthony Iheshiulo. Dalhousie University Halifax, Nova Scotia

 

Anyone interested in growing haskaps for berry production will be interested in this thesis from Halifax. Nova Scotia where Master’s student, Keene Mark-Anthony Iheshiulo attempted to find the optimum levels of soil nutrients and correlated that with tissue nutrient levels. This research is important because it gives growers and gardeners a good diagnostic tool for figuring out if nutrient deficiencies or excess exist. It provides a good marker for applying just the right levels of fertilizer in a season and avoiding wasteful applications of fertilizers. Theses are also great summaries of existing literature, and this one is no exception. It provides a nice overview of the haskap, the importance of macro and micro nutrients in fruit production, and soil and tissue testing.

Balanced nutrition is crucial for haskap (Lonicera caerulea L.) growth, productivity, and economically viable commercial production. However, there are no clearly established soil fertility and leaf tissue nutrient sufficiency levels. A field survey was conducted in 2015 and 2016 on 19 farms in Nova Scotia to identify optimal soil fertility and leaf tissue nutrient levels from 148 paired samples. Plant growth rate, leaf size and chlorophyll content were determined for the variety Indigo Gem after berry harvest in 2016. Using a boundary line approach, nutrient sufficiency levels in soil by Mehlich III extraction were 80-280 kg P2O5 ha-1, 260-570 kg K2O ha-1, 1300-4000 kg Ca ha-1, and 250-510 kg Mg ha-1, while leaf nutrient sufficiency ranges were 2.23-2.96.0% for N, 0.22-0.28% for P, 0.84-1.32% for K, 1.63-2.10% for Ca, and 0.14-0.50% for Mg. Further research is needed to validate fertility and leaf nutrient sufficiency ranges in relation to haskap yield 

The thesis is copyrighted and will not be shared here but is available online. http://dalspace.library.dal.ca/bitstream/handle/10222/73917/Iheshiulo-Ekene-MSc-AGR-April-2018.pdf?sequence=5&isAllowed=y

Cloudberry phytonutrients change with season and cultivar

Seasonal and yearly variation of total polyphenols, total anthocyanins and ellagic acid in different clones of cloudberry (Rubus chamaemorus L.) 2018. Anne Linn Hykkerud1, Eivind Uleberg, Espen Hansen, Marieke Vervoort, Jørgen Mølmann, Inger Martinussen   Journal of Applied Botany and Food Quality 91, 96 – 102 (2018)

Scientists in Norway have done more than any others in cultivating the cloudberry, Rubus chamaemorus. A lot of research on field cultivation as well as cultivar selection have been done in that country. This study continues that research and studies the levels of two phytonutrients: ellagic acid (the most abundant in cloudberry) and total anthocyanin. They examined the content of the berries in four clones, ‘Fjordgull’, ‘Fjellgull’, ‘102’ and ‘306’ growing in  Tromsø 69°39’N 18°57’E.

Interestingly the anthocyanin which are found in small quantities, varied significantly by the seasonal weather patterns. Anthocyanin levels were greatest in cool seasons and lowest when the weather was hot. They also were highest at the beginning of harvest season and lowest at the end and differed also with cultivar. The most important chemical, ellagic acid did not show the same variation with the seasons. Instead, the biggest factor was genetics. The four cultivars tested showed significantly different levels of this chemical, and those levels also varied by year and by harvest time. Berries lose ellagic acid content life harvested after in the season.

The authors concluded that there is a lot that can be done to select for clones of cloudberry with higher levels of these phytonutrients. It also shows how nutrient levels can change drastically from season to season and even within a single season. Lessons for berry pickers? Pick early in the season. 2018. Rubus chamaemorus