Eugenie Kayitesi

Microbial-processing of fruit and vegetable wastes for production of vital enzymes and organic acids: Biotechnology and scopes

Wastes generated from fruits and vegetables are organic in nature and contribute a major share in soil and water pollution. Also, green house gas emission caused by fruit and vegetable wastes (FVWs) is a matter of serious environmental concern. This review addresses the developments over the last one decade on microbial processing technologies for production of enzymes and organic acids from FVWs. The advances in genetic engineering for improvement of microbial strains in order to enhance the production of the value added bio-products as well as the concept of zero-waste economy have been briefly discussed.

Fermented and malted millet products in Africa: Expedition from traditional/ethnic foods to industrial value-added products

ABSTRACT With the prevalent food insecurity in Africa, there is a growing need to utilize the available crops to develop nutritious, affordable and palatable food for the populace. Millet is critical in this role, relative to its abundance in the continent and good nutritional composition. For ages, fermentation and malting have been traditionally used to transform millet into variety of produce. A paradigm shift has however occurred over the years, giving birth to new commercially available products. This review thus appraises and gives an overview of traditional and modern fermented and malted products. Although, millet has been diversified to several products, its major food uses are still restrained to traditional consumers and largely remains underutilized. Considering the potential embedded in this grain, it is important to explore this crop through the application of appropriate modern fermentation and malting technologies. This will ensure the availability of ready to eat (RTE) and ready to use (RTU) food products and to a large extent address the incessant food security challenges plaguing Africa.

Comparison of nutritional quality and sensory acceptability of biscuits obtained from native, fermented, and malted pearl millet (Pennisetum glaucum) flour

The effects of fermentation and malting on the proximate composition, mineral content, amino acids and total phenolic content of pearl millet flour and biscuits were studied. Consumer tests of the biscuits samples were also done using two sets of panelists. The results showed that fermentation and malting improved the crude fiber, crude protein, carbohydrate and energy values of the pearl millet flour. For the biscuit samples, the fermented and malted biscuits had higher moisture, crude protein, crude fiber and energy value with lower fat and ash content as compared to the biscuits obtained from native flour. Fermentation and malting were further observed to increase majority of the essential and non-essential amino acids. Consumer tests among the different set of panelists showed differences in the loading patterns as observed through principal component analysis. In conclusion, this study shows that fermentation and malting improves nutritional, health composition of pearl millet flour as well as the sensorial acceptability of subsequent biscuits.

Microbial processing of fruit and vegetable wastes into potential biocommodities: a review

Abstract The review focuses on some of the high value-end biocommodities, such as fermented beverages, single-cell proteins, single-cell oils, biocolors, flavors, fragrances, polysaccharides, biopesticides, plant growth regulators, bioethanol, biogas and biohydrogen, developed from the microbial processing of fruit and vegetable wastes. Microbial detoxification of fruit and vegetable processing effluents is briefly described. The advances in genetic engineering of microorganisms for enhanced yield of the above-mentioned biocommodities are elucidated with selected examples. The bottleneck in commercialization, integrated approach for improved production, techno-economical feasibility and real-life uses of some of these biocommodities, as well as research gaps and future directions are discussed.

Advances in Fermentation Technology for Novel Food Products

The relevance of fermentation as an important and key aspect of food processing cannot be overemphasized, as it enhances beneficial composition and ensures safety. Fermentation technologies have constantly evolved with advances effectively dealing with the challenges associated with the traditional food fermentation process. Over the years, concerted efforts, intensive scientific research and the advent of modern sophisticated equipment have addressed these challenges and progressed to new approaches for fermentation of foods, subsequently leading to the delivery of novel food products. These advancements are further fueled by competitiveness among industry players based on innovativeness, cost-cutting measures, profit and the understandable desire for process improvement, better yields and quality products. This chapter covers significant advancement and technological applications that can improve food fermentation processes that are applicable for the delivery of better, safer and cost-effective food products.

Bioprocessing of jackfruit (Artocarpus heterophyllus L.) pulp into wine: Technology, proximate composition and sensory evaluation

Major wineries are confined to using grapes as substrate, as a result of which other fruits, especially in the tropical zone, remain underutilised. A wine, from jackfruit (Artocarpus heterophyllus L.) pulp, was prepared by fermenting with wine yeast (Saccharomyces cerevisiae) as starter culture. The wine had the following proximate compositions: total soluble solids, 1.8° Brix; total sugar, 4.32 g/100 ml; titratable acidity, 1.16 g tartaric acid/ 100 ml; pH, 3.52; total phenolics, 0.78 g/100 ml; β-carotene, 12 µg/100 ml; ascorbic acid, 1.78 g/100 ml; lactic acid, 0.64 mg/100 ml and ethanol content of 8.23% (v/v). The jackfruit wine had a DPPH scavenging activity of 32% at a dose of 250 µg/ml. The jackfruit wine was well accepted among consumers as per its organoleptic properties. Principal component analysis reduced the 10 original analytical and proximate variables (TSS, total sugar, TA, pH, phenol, β-carotene, ascorbic acid, lactic acid, ethanol and DPPH scavenging activity) into four independent components which accounted for 83.42% of variations.

Profiling of volatile flavor compounds in nkui (a Cameroonian food) by solid phase extraction and 2D gas chromatography time of flight mass spectrometry (SPME-GC×GC-TOF-MS)

Abstract The objective of this study was to investigate the volatile flavor compounds of nkui, a Cameroonian food, using solid phase microextraction (SPME) and a two‐dimensional gas chromatography time of flight mass spectrometry GC×GC‐TOF‐MS system. Using SPME, volatile compounds were extracted from nkui and analyzed by GC×GC‐TOF‐MS. The data retrieved revealed the presence of flavor volatiles including acids (20%), alcohols (4%), aldehydes (10%), aromatic compounds (4%), esters (7%), furans (4%), ketones (11%), terpenes and terpernoids (27%). Although the terpene compounds were the most predominant, an ester (linalyl acetate) had the highest percentage of 19%, conferring a sweet, green and citrus flavor. Results obtained from this study suggest that the characteristic flavor of nkui was due to the combination of different volatile flavor compounds, which contributed to its aroma. Considering the medicinal importance of these compounds, their presence positions nkui as a vital food source with health benefits and medicinal properties.

Nutritional quality of maize–groundnut composite flours and resultant porridges

Purpose The purpose of this study was to composite maize, a cereal grain with low protein and lysine content, with groundnut a rich source of protein, to improve the nutritional quality of maize–groundnut composite flours and their resultant porridges. Design/methodology/approach Defatted and full fat groundnut flours were used to prepare maize–groundnut composite flours and porridges at the ratio of 100:0, 55:45, 70:30 and 85:15, respectively. They were analyzed for proximate composition, energy value, amino acid and fatty acid profiles. Findings Compositing maize with groundnut significantly (p ≤ 0.05) increased proteins from 10 per cent in maize flour to up to 21 per cent in composite porridge (denoted DFC1). The energy values for composite porridges were 434 Kcal/100 g when compared with 398 Kcal/100 g established for maize porridge alone. Lysine content was three times higher in composite flours than for maize flour, while for composite porridges, lysine was four times higher than in maize porridge. There was an increase of 35 per cent in oleic acid content when maize flour was composited with groundnut flour. Research limitations/implications Further research is required to evaluate the properties of full fat and defatted maize–groundnut porridges and their effects on consumer acceptability. Originality/value It can be concluded that compositing maize with full fat and defatted groundnut has the capability of improving the nutritional quality of cereal-based diets consequently contributing to a significant increase in nutritional security of African populations and those of other developing countries of the world.