Biotechnology in Food Production and Processing

Organic agriculture and foods: advancing process-product integrations

With a doubling of the human population during the last 45 years and Earth's annual resources being already depleted mid-year, it becomes increasingly clear that the food systems need to change. The most common food related needs required are drastic changes of the current food production systems, diet change and food loss/waste reduction. As for agriculture no further land expansion is responsible and more food needs to be grown sustainably on less land and on healthy soils. For food processing, gentle, regenerative technologies have to generate healthy foods based on consumer requirements. Organic (ecological) food production is increasing worldwide but the interface between production and processing of organic foods is still hazy. This paper reviews the history and current state of organic agriculture and organic foods. Existing norms for organic food processing and urgent needs for their gentle, consumer-oriented processing are presented. Key issues such as production systems integration, water efficiency, plant and soil microbiota, biodiversity and supplementary food production systems are discussed. Processing of organic foods using fermentation, microbial/food biotechnological processes and sustainable technologies for retaining desirable nutrients and removing undesirable ones are proposed. Environment and consumer-oriented concepts for future production and processing of human food supplies are proposed.

Food Processing at a Crossroad

Recently, processed foods received negative images among consumers and experts regarding food-health imbalance. This stresses the importance of the food processing-nutrition interface and its relevance within the diet-health debates. In this review, we approach the related questions in a 3-fold way. Pointing out the distinguished role food processing has played in the development of the human condition and during its 1.7 million year old history, we show the function of food processing for the general design principles of food products. Secondly, a detailed analysis of consumer related design principles and processing reveals questions remaining from the historical transformation from basic cooking into advanced food technology. As a consequence, we analyze new and emerging technologies in relation to their contributions to food-health impacts. During the last 35 years, new and emerging food technologies have initiated a paradigm shift away from conventional process methodologies to gentler, non-thermal processing. Reducing the existing uncertainties in the assessment of impact of technology like "minimal processing," we propose the use of the newly established ISO standard for natural food ingredients as a "reference point." Finally, we assess the usefulness of recently proposed classification systems, e.g., NOVA classification, based on comprehensive insights of recently published nutritional analysis of those classifications. This paper calls for a radical change and worldwide adaptation of the key research and developmental areas tackling the grand challenges in our food systems.

Value-added products from underutilized fish species

Fish is a rich source of easily digestible protein that also provides polyunsaturated fatty acids, vitamins, and minerals for human nutrition. Nonetheless, a large proportion of total landed fish remains unused due to inherent problems related to unattractive color, flavor, texture, small size, and high fat content. Most of these underutilized fish belong to the abundantly available pelagic species, which are landed as bycatch, and some are unconventional species such as krill. Although some species are used industrially for fish meal manufacture, a need for their conservation and utilization for human consumption has been recognized in order to prevent post-harvest fishery losses. Recovery of flesh by mechanical deboning and development of value-added products are probably the most promising approaches. This article discusses various possibilities for product development using mince from low-cost fishery resources. These include surimi and surimi-based products, sausages, fermented products, protein concentrates and hydrolysates, extruded products, and biotechnological possibilities. The dual advantages of this approach, namely, finding ways for better utilization of low-value fish species and providing protein- rich convenience foods, have been pointed out. However, the key to the success of this approach depends largely on the market strategies utilized.

Chirality of amino acids of microorganisms used in food biotechnology

Bacteria of the genera Acetobacter, Bifidobacterium, Brevibacterium, Lactobacillus, Micrococcus, Propionibacterium, and Streptococcus, which are used as so-called starter cultures for the large-scale production of fermented foods and beverages in food biotechnology, have been investigated for the chirality of their amino acids (AA) by gas chromatography (GC). Bacteria were grown in complex media, centrifuged, and washed with 0.85% aqueous NaCl. Aliquots were totally hydrolyzed (6 M HCl, 110 degrees C, 18 h), or extracted with 70% aqueous ethanol in order to isolated free AA. The AA were adsorbed on Dowex WX 8 cation-exchanger, eluted with 4 M ammonia and converted into their N(O)-trifluoro-acetyl(TFA) 2-propyl esters or TFA methyl esters. The AA derivatives were investigated by capillary GC using the chiral stationary phases Chirasil-L-Val, Chirasil-D-Val, and Lipodex E. Besides L-AA, in all bacteria D-amino acids (D-AA) were detected; those in the highest relative amounts were D-Ala and D-Asp (occurring in all bacteria) and, in several cases, D-Glu. Lower, but significant amounts of other D-AA such as D-Ser, D-Pro, D-Val, D-Thr. D-Ile, D-Leu, D-Met, D-Phe, D-Tyr, D-Orn, and D-Lys were also detected in certain bacteria. These findings explain the origin of D-AA found in all fermented foods and drinks produced with the aid of bacterial starter cultures.

[Genetic engineering]

This paper deals with the progress made in genetic engineering techniques, capable of altering the genetic potential of an organism, either by the introduction or the suppression of new structural genes. Some of the general applications are described as are also, more particularly, their uses in the field of medicine. A critical analysis of the benefits and risks involved is also undertaken.

[Recent developments in selected areas of food biotechnology]

With respect to literature and own experiments a review is given of the current international knowledge in special fields of food biotechnology. In this context nutritionally and physiologically relevant problems find particular consideration. After an introduction the development in technology, genetic engineering and protein technology is discussed. Then the following topics are dealt with: Single cell proteins (mushrooms, yeasts, bacteria, fungi, phototrophic microorganisms), soluble enzymes, enzyme inhibitors, immobilized systems (enzymes, cells, new processes and products), amino acids, sweeteners, microbial polysaccharides as hydrocolloids, organic edible acids, plant cell and tissue cultures and flavourings (enzymes, microorganisms, plant systems).

Influence of modifying agents on enzyme inactivation studies. An analysis using a series mechanism and a form of the hill-type equations

A series deactivation model is utilized to theoretically examine the influence of different modifying agents on enzyme deactivation kinetics. A form of the Hill-type equation is used to describe the effect of the modifying agents on the model parameters. Modification-induced inactivation equations are presented for the acetylation and succinylation of E. Coli asparaginase, for the site-specific reagent and substrate modification of flavocytochrome b(2) from Baker's yeast, and for the guanidinium chloride inactivation of cathepsin D. The analysis of more data for these and other enzymes would help further substantiate the technique presented and enhance the applicability of the model.