Monthly Archives: June 2018

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.

 

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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