Sunday, November 5, 2017

Cereal Processing By-Products Within the Biorefinery Concept


Cereal grains comprise the principal component of human diet for thousands of years and therefore their processing represents a big asset of the food production chain. Wheat, rice, oat, barley and corn processing via dry and wet milling, pearling and malting includes complex procedures that generate an important amount of by-products that differ in their physical state and chemical composition.
Cereal processing by-products represent abundant and low-cost resources of phytochemicals (e.g. carbohydrates, proteins, dietary fibre, lipids, vitamins, polyphenols, inorganic and trace elements) with potential nutraceutical and pharmaceutical applications. To this line, their re-utilization and upgrade to high added-value applications is a great challenge towards the sustainable development of the agro-food sector for the years to come.
Oat processing and the alternative optionsThe target compounds and substrates are plenty and have been covered adequately through the whole book. Oat, its processing by-products and healthy components is a typical example of the available valorization and upgraded choices. Oats possess high amounts of water soluble fibers and particularly β-glucan (e.g. 2.2-7.8 g/100 g) as well as proteins (11-20 g/100 g). Their nutritional advantages in spite of diabetes and the control of blood cholesterol level have been attributed to the contained β-glucan.
To this line, the attribution of cereal β-glucan as functional ingredient has increased the interest concerning their incorporation in food formulations. Oat grains have been subjected to amylase hydrolysis (converting starch, carbohydrates and dietary fibers to maltose and β-glucan) in order to develop nondairy products. This process is monitored via enzyme kinetics modeling that optimizes the viscoelastic behavior of hydrolysates and simulates biodegradation processes of multienzymatic system based on cultures, e.g. hydrolysis of starch wastes.
Carbohydrate hydrolysis generates a drink that is consumed alternatively to milk products due to the lactose intolerance and cholesterol content issues of human populations, and a by-product (oat mill waste), which is usually dried and utilized as animal feed. The latest is rich in proteins and β-glucan that could be recovered using extraction and membrane technologies and utilized further in different applications, e.g. to replace fat of yoghurt and cheese.
Read full article in my Elsevier SciTech Connect Blog.

Friday, November 3, 2017

The Trend of Polyphenols

In the past 10 years, the growing interest of consumers has arised to a number of “superfoods”, which has been motivated by their high content of “polyphenols”. These compounds constitute a heterogeneous group of molecules which differentiate according to their chemical structure.

Polyphenols is a collective term for several sub-groups of compounds, but the use of this term has been somewhat confusing and its implied chemical structures are often vague even to researchers. Even today the scientific community is not consistent with a universal use of the term denoting plant polyphenols, since some call them plant phenols while some others use the term polyphenols.
The first definition of plant polyphenols in the scientific literature pertains to this initial utilization of polyphenolic plant extracts. As these compounds were highly required in the leather industry, considerable efforts were devoted from the beginning of the 20th century onwards to the study of the chemistry of tanning plant extracts in an attempt to tackle the structural characterization of their polyphenolic constituents.
Research on plant polyphenols shifted gears after 1945, as the discovery of paper chromatography and more and more other advanced analytical techniques made it possible to separate in numerous individual constituents.
In 1957 an industrial chemist Theodore White, pointed out that the term “tannin” should strictly refer to plant polyphenolic materials having molecular masses between 500 and 3000 Da and a sufficiently large number of phenolic groups to be capable of forming hydrogen-bonded cross-linked structures with collagen molecules (the act of tanning).
Today, the main reason for the interest of scientists and consumers for polyphenols is the recognition of their antioxidant properties, their great abundance in our diet, and their probable role in the prevention of various diseases associated with oxidative stress, such as cancer and cardiovascular and neurodegenerative diseases. Due to the considerable diversity of their structures, polyphenols are considered even more efficient than other antioxidants.
Read full article in My Elsevier SciTech Connect Blog.

Tuesday, September 5, 2017

Sustainable Food Systems Means Improving Production and Processing

Until the end of the 20th century, food loss and disposal of food waste were not evaluated as matters of concern. The prevalent policy was mainly to increase food production, without improving the efficiency of the food systems. This fact increased generation of food lost or wasted along supply chains.
In the 21th century, escalating demands for processed foods have required identification of concrete opportunities to prevent depletion of natural resources, restrict energy demands, minimize economic costs as well as reduce food losses and wastes. Besides, recent changes in the legislative frameworks and environmental concerns have stimulated industry to reconsider their management policy and in some cases to face the concept of “recovery” as an opportunity.
This tendency is becoming a major item for the food industry around the world, as resources become more restricted and demand grows. Indeed, food industry is increasing attention towards sustainability, which has been has been developed into a trendy word characterizing a frame of advances and modernization in the years to come. However, sustainability is neither easy to specify nor to implement.
In theory, it reflects the principle that we must meet the needs of the present without compromising the ability of future generations to meet their own needs. For instance, food processing ensures that the resources required producing raw food materials and ingredients for food manufacturing are used most efficiently. Responding to this goal, sustainability requires the maximum utilization of all raw materials produced and integration of activities throughout all the production-to-consumption stages.
Read full article in my Elsevier Scitech Connect Blog.

Thursday, August 3, 2017

Sustainable Management of Olive Mill Wastewater: Treatment or Valorisation?


Olive oil is obtained from olive fruit by mechanical procedures, whereas its production involves one of the following extraction processes: i) discontinuous (press) extraction, ii) 3-phase centrifugal extraction or iii) 2-phase centrifugal extraction. Each of these processes generates in different forms and compositions.
The traditional olive pressing and the three phases continuous systems produce three streams: olive oil, olive cake (or kernel) and olive mill wastewater (OMWW). The annual world OMWW production is estimated between 10 and 30 million m3. The discontinuous process (not used often anymore) produces less but more concentrated wastewater (0.5–1m3 per 1000 kg) than the centrifugation process (1–1.5m3 per 1000 kg). The 2-phase centrifugal system was introduced during the 1990s in which the olive paste is separated into phases of olive oil and wet pomace (sludge by-product) that enables reduction of the volume of OMWW. Wet olive pomace is usually further extracted with n-hexane yielding olive cake oil, although it has no significant value because of the required energy for the drying process.
OMWW is a dark-colored, acidic (3< pH value <5.9) suspension of three phases: water, oil and solids (smashed particles of olive paste and kernel). It has a characteristic unpleasant odour and high organic content, whereas is claimed to be one of the most polluting waste produced by the agro-food industries. Typically OMWW consists of: 83-94% water, 0.4-2.5% mineral salts, 0.03–1.1% lipids and 4-16% organic compounds such as carbohydrates (2-8 g/100 g), pectin, mucilage, lignin and tannins.

Read full article in my Elsevier SciTech Connect Blog here.

Tuesday, August 1, 2017

Handbook of Grape Processing By-products Book – Authors’ Team Acknowledgments


After its launch few months ago, the Handbook of Grape Processing By-products  is continuously raising interest among researchers, academics, students, professionals and industrial partners activated in the field. Indeed, thousands’ of colleagues have already joined our LinkedIn and Facebook communities, participate in our open forums, discuss their needs, make questions, refer their case scenarios, indicate their problems and finally look for solutions and consulting in our interactive Food Waste Recovery – Open Innovation Network.
Book Presentation
A detailed explanation of the key features and hints of the book is accessible via an online book presentation which was organized on 20th of June by ISEKI Food Association (IFA) and watched live by numerous colleagues around the world. This was also an opportunity to catch up with colleagues and meet our audience. A recording of this book presentation can be viewed in the following video

Authors’ Team Acknowledgments
All these activities are organized by the FWR Group and volunteering actions of experts in the field. Therefore, I would like to take this opportunity to thank all group members and authors’ team for their fruitful collaboration and high quality work in bringing together different topics and technologies in an integral and comprehensive text.
Read full article here.

Monday, June 5, 2017

Factors Affecting the Bioaccessibility and Bioavailability of Bioactive Compounds


Bioactive compounds are found in fruits, vegetables and whole grains. They include an extremely heterogeneous class of compounds (polyphenolic compounds, carotenoids, tocopherols, phytosterols and organosulfur compounds) with different chemical structures (hydrophilic or lipophilic), distribution in nature (specific to vegetable species or ubiquitous), range of concentrations both in foods and in the human body, possible site of action, effectiveness against oxidative species, and specificity and biological action.
Several factors interfere with the bioavailability of antioxidants, such as food source and chemical interactions with other phytochemicals and biomolecules present in the food include some of the factors interfering with the bioavailability of bioactive compounds. For example, fruit antioxidants are commonly mixed with different macromolecules such as carbohydrates, lipids, and proteins to form the food matrix. In plant tissue, carbohydrates are the major compounds found, mainly in free and conjugated forms.
After consumption, the nutrients that are present in a food or drink are released, absorbed into the bloodstream and transported to their target tissues. Different nutrients differ in their bioavailability, which means that they are not utilized to the same extent. Release of the nutrient from the food matrix, effects of digestive enzymes in the intestine, binding and uptake by the intestinal mucosa, transfer across the gut wall to the blood or lymphatic circulation, systemic distribution and deposition, metabolic and functional use, excretion can affect nutrient bioavailability. It is mediated by external (e.g. characteristics of the food matrix, chemical form of the nutrient etc) and consumer internal (e.g. gender, age, nutrient status and life stage) factors. The bioavailability of macronutrients (carbohydrates, proteins and fats) is usually very high, e.g. more than 90% of the amount ingested.
Read full article in my Elsevier Scitech Connect Blog.

Saturday, May 27, 2017

“Olive Mill Waste” Book Presentations & Author Team Acknowledgments

After its launch five months ago, the Olive Mill Waste book is continuously raising interest among researchers, academics, students, professionals and industrial partners activated in the field.
Trying to catch up with colleagues, meet our audience as well as explain in details the key features and hints of the book, an online book presentation was organized on 4th April 2017 by ISEKI Food Association (IFA) watched live by hundreds of colleagues around the world. A recording of this book presentation can be viewed in the following video:
https://www.youtube.com/watch?v=UIRd-wUpBZo&t=10s
Authors’ Team Acknowledgments
All these activities are organized by the FWR Group and volunteering actions of experts in the field. Therefore, I would like to take this opportunity to thank all group members and authors’ team for their fruitful collaboration and high quality work in bringing together different topics and technologies in an integral and comprehensive text.
Read full article here.