Search results
1 – 10 of 769Nelson Chanza and Walter Musakwa
Against a milieu of fragmented research that documents indigenous practices related to food security, and the heterogeneous settings from which the studies have been conducted…
Abstract
Purpose
Against a milieu of fragmented research that documents indigenous practices related to food security, and the heterogeneous settings from which the studies have been conducted, this study aims to synthesize the evidence of indigenous knowledge-food security nexus to strengthen the call for the revitalization of indigenous knowledge (IK) as part of the mechanisms to manage food security challenges being aggravated by climate change.
Design/methodology/approach
Drawing on insights from sub-Saharan Africa (SSA), this study reviews 122 articles accessed from the Web of Science and Scopus databases, which covered indigenous methods used for producing, gathering, processing, preserving and storing diverse food sources that indigenous people deploy in securing their food systems.
Findings
The surge in attention to focus on IK-food security nexus tends to be influenced by the growing acknowledgement of climate change impacts on food systems. Essentially, the IK-based practices adopted address all the four food security pillars that are specified by the Food and Agricultural Organization (FAO) as availability, accessibility, utilization and stability. The main motivation behind the continued use of IK-based ways relates largely to the interest to be food secure against climatic shocks and partly to the desire to maintain people’s food cultures and food sovereignty.
Originality/value
This study deploys the food security pillars provided by the FAO (2012) to demonstrate that IK-based ways of food management are capable of addressing all the four food security dimensions, a critical observation toward revitalizing IK in managing growing food security challenges that are intensified by climate change in SSA.
Details
Keywords
Nomusa R. Dlamini and Shadreck Dube
The aim of the study is to determine the microbial, physico‐chemical and nutritional changes that take place during the four‐day traditional preparation of wine from the fruits of…
Abstract
Purpose
The aim of the study is to determine the microbial, physico‐chemical and nutritional changes that take place during the four‐day traditional preparation of wine from the fruits of Marula (Sclerocarya birrea subspecies Caffra) tree in Zimbabwe. It must be noted that Marula is documented as a drought‐resistant plant.
Design/methodology/approach
The fruits used in the study were taken from four trees growing in different locations. The fermenting microbial populations were isolated using potato dextrose, tomato juice and nutrient agars, and then identified to genus level using simple biochemical tests. The physico‐chemical changes determined were pH, titratable acidity, sugar and alcohol content. The alcohol content was determined using the Anton Paar beer analyzer, while nutritional changes, evaluated as changes in ascorbic acid (vitamin C) levels, were determined using the 2, 6 dichlorophenolindophenol titrimetric method.
Findings
During fermentation there was a gradual decrease in the bacterial population, and an increase in yeast counts. The pH and sugar contents decreased, while the average alcohol content increased to an average 2 per cent. The fermented Marula juice retained 72 per cent of the initial ascorbic acid content (a decrease from 133 to 96 mg/100 g) compared with orange juice subjected to similar conditions, which retained 40 per cent ascorbic acid levels (decrease from 60 to 24 mg/100 g).
Originality/value
The low pH of Marula wine could contribute to the microbiological safety of the product and relative stability of ascorbic acid. Marula wine produced after four days of fermentation is still an importance source of ascorbic acid.
Details
Keywords
Wenwen Zhang, Peifang Weng and Zufang Wu
Mixed fermentation with Saccharomyces cerevisiae and non-Saccharomyces yeasts has become an oenlogical tool to improve wines’ organoleptic properties. However, the maximum…
Abstract
Purpose
Mixed fermentation with Saccharomyces cerevisiae and non-Saccharomyces yeasts has become an oenlogical tool to improve wines’ organoleptic properties. However, the maximum utilization of this method is dependent upon understanding the influence of mixed cultures on the physiology of S.cerevisiae and non-Saccharomyces yeasts.
Design/methodology/approach
In this study, the supernatants from 48 h mixed-culture fermentation were added to the pure cultures of Issatchenkia orientalis and Saccharomyces, respectively. And the authors used RNA sequencing to determine the transcriptome change of I.orientalis and S.cerevisiae in a mixed culture.
Findings
The results showed that multiple genes associated with cell growth and death were differentially expressed. Genes related to biosynthesis of amino acids were enriched among those upregulated in the mixed-fermentation supernatant. Meanwhile, the differential expression level of genes encoding enzymes essential for formation of aroma compounds was found in the single and in the mixed fermentation. The high expression level of molecular chaperones Hsp70, Hsp90 and Hsp110 suggests that metabolites of mixed-culture fermentation may lead to aggregation of misfolded proteins. Moreover, upregulation of ethanol dehydrogenase I ADH1 in the mixed-culture fermentations was highlighted.
Originality/value
This is the first time that RNA-seq was used to analyze changes in the transcriptome of mixed cultures. According to the results the authors’ manuscript provided, an integrated view into the adaptive responses of S.cerevisiae and non-Saccharomyces yeasts to the mixed-culture fermentation is benefit for the potential application of S.cerevisiae and non-Saccharomyces yeasts in fruit wine brewing.
Details
Keywords
Esther Gyedu-Akoto, Eric Kumi Asare, Stephen Yaw Opoku, Abu Mustapha Dadzie and Emmanuel Ofosu-Agyei
Roasted coffee provides a complex blend of different flavours which produce a range of sensory qualities. With the development of protocols for the production of fresh juices…
Abstract
Purpose
Roasted coffee provides a complex blend of different flavours which produce a range of sensory qualities. With the development of protocols for the production of fresh juices, jams and marmalades from cocoa and cashew pulp juices at Cocoa Research Institute of Ghana, this paper aims to study the effects of roasted coffee powder on fermented cocoa and cashew juices to diversify the uses of these two juices.
Design/methodology/approach
Cocoa and cashew juices were fermented with the incorporation of 2% roasted coffee powder using Saccharomyces cerevisiae yeast starter. The fermenting juices were monitored by measuring pH, temperature, specific gravity and titratable acidity. At the end of the fermentation, the juices were poured into clean, sterilized containers to mature. They were then analysed for their physicochemical, microbiological and sensory qualities. These were repeated with cocoa and cashew juices without coffee powder to determine the effects of the roasted coffee on the fermented juices.
Findings
The addition of roasted coffee powder to cocoa and cashew juices did not have any significant effect on the fermentation performance of the juices. Three out of the four juices took a total of 13 days to complete fermentation with an average final specific gravity of 0.99. The quality of the fermented juices was not compromised by microbial activities. However, the addition of roasted coffee powder reduced the alcohol content of fermented cocoa juice from 9.0 to 5.0% and that of cashew from 11.0% to 7.5%. Sensory analysis using untrained panellists, who were ordinary consumers, showed significant differences among the four fermented juices in terms of appearance, taste and aroma. Their mean scores for coffee aroma ranged from 0.3 to 2.0 with coffee incorporated fermented juices having higher rankings.
Originality/value
These findings have shown the possibility of processing cocoa and cashew juices, which under normal circumstances would have been discarded along their value chains, into coffee-flavoured wines. They are also important to cocoa, cashew and coffee farmers, processors, as well as wine enthusiasts.
Details
Keywords
Yu-Ming Chung, Shao-Yu Lee, Yung-Kai Lin, Yung-Hao Lin, Mohamed El-Shazly, Yung-Hsiang Lin and Chi-Fu Chiang
Rambutan (Nephelium lappaceum), a ubiquitous fruit in Southeastern Asia, was rich in vitamins and phytochemicals, which were beneficial for improving of skin conditions. The…
Abstract
Purpose
Rambutan (Nephelium lappaceum), a ubiquitous fruit in Southeastern Asia, was rich in vitamins and phytochemicals, which were beneficial for improving of skin conditions. The fermentation process increased phytochemicals and antioxidant capacity. Thus, the purpose of this paper is to examine whether phytochemicals can be increased through the fermentation process of rambutan extracts to improve skin aging.
Design/methodology/approach
In this study, the authors used the three stages of fermentation with Saccharomyces cerevisiae, Lactobacillus plantarum TCI028 and Acetobacter aceti under red light to develop a fermented rambutan extract.
Findings
The level of polyphenols of red-light-based fermented rambutan extract (RLFRE) were significantly increased 108.9% (p < 0.01) and 97% (p < 0.01) compared with fermented rambutan extract (FRE) and pure rambutan extract (RE), respectively. The human skin fibroblasts treated with 0.03 or 0.06% of RLFRE can significantly decrease reactive oxygen species (ROS) levels by 0.74- (p < 0.001) and 0.84-fold (p < 0.001) compared with H2O2 group, respectively. And 0.03% of RLFRE can significantly increase in elastin content by 1.13-fold (p < 0.05). Also, ten compounds were identified including one new phenolic compound and nine known compounds from RLFRE. Moreover, red light could enhance the levels of compounds 4, 9 and 3 by 5, 2.5 and 2.5-fold, respectively, relative to the results of FRE. The last, RLFRE isolated compounds significantly facilitated the elastin content on fibroblast (compound 1, 7, 9, 10 compared with control: p < 0.001, compound 2 compared with control: p < 0.001).
Originality/value
In short, this was the first study to unveil that the red-light-based fermentation can enrich the antioxidant content in a rambutan extract and its product had the potential to be developed a functional product for health-promoting effects such as skin aging.
Details
Keywords
This study aims to determine the probiotic potential of Lactobacillus rhamnosus GR-1 from Fiti sachets, in four widely consumed pulses, namely, black-eyed pea, pigeon pea, kabuli…
Abstract
Purpose
This study aims to determine the probiotic potential of Lactobacillus rhamnosus GR-1 from Fiti sachets, in four widely consumed pulses, namely, black-eyed pea, pigeon pea, kabuli chickpea and desi chickpea. The secondary objective was to determine the viability of the fermented pulses during 21 days of storage at 4°C.
Design/methodology/approach
Each pulse sample was mixed with a Fiti sachet (one gram of freeze-dried consortium of Lactobacillus rhamnosus GR-1 and Streptococcus thermophilus C106) and fermented for up to 120 h. To assess the samples’ storage potential, they were refrigerated at 4°C for 21 days. Microbial enumerations and pH measurements were collected during fermentation and storage to determine the viability and fermentation potential of Lactobacillus rhamnosus GR-1 and Fiti, respectively.
Findings
There was a significant (p = 0.01) difference in mean microbial counts in all pulse samples throughout fermentation. At 24 h of fermentation, the mean bacterial count of Lactobacillus rhamnosus GR-1 in black-eyed pea, pigeon pea, kabuli chickpea and desi chickpea were 1.32 × 109 ± 0.11, 1.01 × 109 ± 0.16, 1.52 × 109 ± 0.14 and 0.80 × 109 ± 0.05 CFU/mL, respectively. Fermentation of pigeon pea, kabuli chickpea and desi chickpea at 48 h yielded the highest bacterial count for Lactobacillus rhamnosus GR-1 while black-eyed pea reached its highest bacterial count at 72 h of fermentation. The bacterial concentration of all pulse samples remained at around 109 CFU/mL during the refrigeration period of 21 days at 4°C. Furthermore, the pH of all pulse samples were below 4.6 during both fermentation and refrigerated storage.
Originality/value
Since 2004, the Fiti initiative has economically empowered hundreds of women in East Africa by teaching them how to produce and sell probiotic yogurt containing Lactobacillus rhamnosus GR-1. As a result, Fiti probiotic yogurt was made accessible to vulnerable populations in East Africa who face malnutrition, infectious diseases and environmental toxins. Because of recent climatic changes, milk has become more expensive and inaccessible for local communities. Furthermore, this study found that black-eyed pea, pigeon pea, kabuli chickpea and desi chickpea can be viable and non-diary probiotic alternatives to the Fiti probiotic yogurt in Eastern Africa. This is also the first study of its kind to provide preliminary evidence showing pulses as non-dairy alternatives to Fiti probiotic yogurt.
Details
Keywords
Fernanda Silva Farinazzo, Tiago Bervelieri Madeira, Maria Thereza Carlos Fernandes, Carolina Saori Ishii Mauro, Adriana Aparecida Bosso Tomal, Suzana Lucy Nixdorf and Sandra Garcia
The objective of this study was to evaluate the influence of Saccharomyces boulardii on the kinetics of fermentation for organic and conventional apple pulp and to verify the…
Abstract
Purpose
The objective of this study was to evaluate the influence of Saccharomyces boulardii on the kinetics of fermentation for organic and conventional apple pulp and to verify the effect of the antioxidant quercetin on the response to cellular oxidative stress.
Design/methodology/approach
The kinetic parameters, the content of phenolic compounds, the quantity of quercetin and the antioxidant activity were determined during the fermentation process. The effect of quercetin on cellular oxidative stress was also investigated.
Findings
The content of phenolic compounds, the antioxidant activity and the quercetin concentration were higher in the organic fermented apple pulp (ORG) than in the conventional fermented apple pulp (CON). However, both apple pulps were considered ideal substrates for the growth of S. boulardii, suggesting that they are potentially probiotic. After fermentation, the quercetin concentration in the ORG treatment and YPDQ treatment (YPD broth with 0.1 mg quercetin rhamnoside/mL) increased viability by 9%, while in the CON treatment generated there was an increase of 6% in viability, compared to the YPD control treatment (YPD broth).
Originality/value
The high concentration of quercetin in the organic apple pulp supports the proposal that quercetin reduces the oxidative stress mediated by reactive oxygen species through its antioxidant action on S. boulardii that have similarities to mammalian eukaryotic cells. These findings suggest that fermented organic apple pulp could be consumed as a potential non-dairy probiotic product.
Details
Keywords
J.O. Olajide, A.A. Adedeji, B.I.O. Ade‐Omowaye, E.T. Otunola and J.A. Adejuyitan
This paper aims to focus on the prospects of incorporating a non‐thermal process (high intensity electric field pulses, HELP) into food processing and preservation methods in…
Abstract
Purpose
This paper aims to focus on the prospects of incorporating a non‐thermal process (high intensity electric field pulses, HELP) into food processing and preservation methods in developing countries. Besides, it is to create awareness to food processors and motivate researchers in developing countries to generate more data on the technology.
Design/methodology/approach
This is based on the review of the various successful applications of HELP process in inactivation of micro‐organisms for the purpose of preservation. The adaptability of the process to plant food processing was also reviewed. Potential areas of application in developing countries were also highlighted and discussed.
Findings
The present findings reveal possible applications of HELP to food processing in developing countries such as fermentation, fruit and vegetable processing, and dehydration of tropical food.
Originality/value
The paper has indicated that the poor energy system in developing countries has made drying and fermentation techniques appropriate methods of food processing. Therefore, HELP technology offers good potentials for both food processing and preservation and as adjunct to other processes such as fermentation and drying.
Details
Keywords
Scientists have often been accused of a desire to reduce the human diet to a pill or powder form “to be taken daily with water at meal times.” Whatever truth there might be in the…
Abstract
Scientists have often been accused of a desire to reduce the human diet to a pill or powder form “to be taken daily with water at meal times.” Whatever truth there might be in the allegation, it is an actual fact that more and more foods are being proved suitable for preservation in dried form. This is partially a logical development of the processes of food preservation, which are largely the concentration of food products for convenience in transport and storage, and partially the results of special war‐time demands. The need for concentrated nourishment is never greater than under conditions of war stress, and the present serious pressure upon Allied shipping facilities has further tended to increase the need for foods that occupy the least possible space. On the average, one pound of fully dehydrated food is the equivalent of fifteen pounds of the same product in its original form. Thirty dozen eggs in the shell, packed and created for shipment, occupy 2¼ cubic feet; dried, the same number take slightly more than one‐half cubic foot. The saving in ships and cargo space is obvious. While the problem of shipping space has been a major factor in the stimulated interest in dehydration, other elements in the existing situation have also had their influence. In Great Britain, under constant threat of invasion, it has been essential to build up reserve stocks of food throughout the country, often under storage conditions that are far from ideal. The serious shortage of tin has restricted the use of ordinary canning methods to foods which cannot, at the present stage of research, be preserved in any other form. A further stimulus has been given by the necessity of providing concentrated foods for paratroops and commando units, which must be entirely self‐sufficient when in action. Special rations are prepared which provide meals for two or three days, yet weigh only a few pounds. Drying is the oldest known form of food preservation, in fact it may be termed the natural method of preservation. Nature herself uses it. On the average, seeds, grains and nuts contain less than 10 per cent. of moisture, regardless of the amount which may be present at earlier stages of growth. The very existence of vegetable life from year to year is in the final analysis dependent upon this lack of moisture which inhibits the growth of bacteria and moulds. Perhaps by some accident, perhaps by imitation of the natural process, man early began to preserve food by drying, either in the sun or by artificial heat. Robinson Crusoe's raisins and the dried apples of our pioneer ancestors leap at once to the mind. Dried fruits and fish, jerked and smoked meats are all preserved by the removal of some part of their original water content. Sometimes this is the sole process, sometimes it is combined with other methods, as salting or pickling. In recent years, however, the preservation of foods by canning, refrigeration, and latterly by quick‐freezing has largely replaced the earlier method. Natural or artificial drying methods have in the past permitted the storage of food and the retention of a part of its nutritive value at the expense of flavour and colour. Everyone knows the difference between the flavour and texture of sweet corn in the milky stage and that which has ripened further, i.e., begun to dry out. In the case of such products we have largely come to prefer the dried flavour, even where we can know the so‐called fresh flavour. Some artificially dried or semi‐dried foods have, in fact, retained their place in the modern diet in direct competition with the fresh form, not as substitutes, but as independent food products in their own right. Such fruits as dates, figs, prunes and raisins are perhaps the best examples. No one expects raisins to take the place of grapes or prunes to have the same flavour as plums. These so‐called dried fruits are, however, really only semi‐hydrated. They retain from 20 to 25 per cent. of their moisture; only enough has been removed to ensure their keeping qualities. While they are a concentrated product, the process has not been carried to the point of complete transformation into the solid form. Jerked or dried meat and such products as pemmican are also among the oldest forms of preserved food, and jerked beef is still extensively produced in many countries. A more generally known form of meat product is meat extract. There are a number of famous brands, available either as a thick syrupy liquid or in a solid cube. The keeping property is implicit in its low water content, usually about 15 per cent. These extracts are prepared by removal of the fat and albumen, the addition of salt and evaporation in vacuum. One pound is ordinarily obtained from twenty‐five pounds of lean meat. Packing companies in the United States report that experimental methods of producing a true dehydrated meat, one which can be restored to its normal character, have been successful, at least in regard to beef. Pork is apparently too fat for such treatment. If the process works on a commercial scale as successfully as in the experiments, additional savings in shipping space will be realised. It is estimated that one ship could carry as much meat as ten cargo vessels were able to transport during the last war. Among other concentrated foods that go back to antiquity are the milk products, butter and cheese. These belong to the class which has little relation in either flavour or texture to the original from which they are made. Cheese is a product of fermentation as well as drying, while butter is additionally protected by salt and by refrigeration in storage and transport. Thus, while the removal of water is an important step in their manufacture, they cannot be considered dried foods. Recent reports from New Zealand indicate that butter is now entering this category. As a result of research which antedates the war, the New Zealand Dairy Research Institute has perfected a method of dehydrating butter. The British Government has contracted to purchase 20,000 tons during 1942 and 1943. A trial shipment of 400 tons was made last year and was well received. According to a report from the Canadian Trade Commissioner in New Zealand, the process was developed originally in order to reach markets not served by refrigerator ships. The dislocation of the shipping facilities between New Zealand and Great Britain has eliminated the usual means of sending butter. The new product, however, can be shipped as general cargo on any ship that may be available. The dried butterfat can be used directly by industrial food manufacturers and its conversion into table butter is simply adding a matter of water and salt. Not only will it serve a valuable war‐time purpose of providing Great Britain with needed fats, but it will also relieve the position of dairy farmers in New Zealand. After the war it is considered possible that the original purpose of marketing in countries without refrigerator service may continue to absorb available supplies.
Elsa Cherian, M. Dharmendira Kumar and G. Baskar
The purpose of this paper is to optimize production of cellulase enzyme from agricultural waste by using Aspergillus fumigatus JCF. The study also aims at the production of…
Abstract
Purpose
The purpose of this paper is to optimize production of cellulase enzyme from agricultural waste by using Aspergillus fumigatus JCF. The study also aims at the production of bioethanol using cellulase and yeast.
Design/methodology/approach
Cellulase production was carried out using modified Mandel’s medium. The optimization of the cellulase production was carried out using Plackett-Burman and Response surface methodology. Bioethanol production was carried out using simultaneous saccharification and fermentation.
Findings
Maximum cellulase production at optimized conditions was found to be 2.08 IU/ml. Cellulase was used for the saccharification of three different feed stocks, i.e. sugar cane leaves, corn cob and water hyacinth. Highest amount of reducing sugar was released was 29.1 gm/l from sugarcane leaves. Sugarcane leaves produced maximum bioethanol concentration of 9.43 g/l out of the three substrates studied for bioethanol production.
Originality/value
The present study reveals that by using the agricultural wastes, cellulase production can be economically increased thereby bioethanol production.
Details