Physical losses could partially explain modest carotenoid retention in dried food products from biofortified cassava

Gari, a fermented and dried semolina made from cassava, is one of the most common foods in West Africa. Recently introduced biofortified yellow cassava containing provitamin A carotenoids could help tackle vitamin A deficiency prevalent in those areas. However there are concerns because of the low retention of carotenoids during gari processing compared to other processes (e.g. boiling). The aim of the study was to assess the levels of true retention in trans–β-carotene during gari processing and investigate the causes of low retention. Influence of processing step, processor (3 commercial processors) and variety (TMS 01/ 1371; 01/1368 and 01/1412) were assessed. It was shown that low true retention (46% on average) during gari processing may be explained by not only chemical losses (i.e. due to roasting temperature) but also by physical losses (i.e. due to leaching of carotenoids in discarded liquids): true retention in the liquid lost from grating negatively correlated with true retention retained in the mash (R = -0.914). Moreover, true retention followed the same pattern as lost water at the different processing steps (i.e. for the commercial processors). Variety had a significant influence on true retention, carotenoid content, and trans-cis isomerisation but the processor type had little effect. It is the first time that the importance of physical carotenoid losses was demonstrated during processing of biofortified crops

CHAPTER 4 MICRONUTRIENT (PROVITAMIN A AND IRON/ZINC) RETENTION IN BIOFORTIFIED CROPS

ABSTRACT For biofortification to be successful, biofortified crops must demonstrate sufficient levels of retention of micronutrients after typical processing, storage, and cooking practices. Expected levels of retention at the breeding stage were verified experimentally. It was proven that the variety of biofortified crop, processing method, and micronutrient influence the level of retention. Provitamin A is best retained when the crops are boiled/steamed in water. Processing methods that are harsher on the food matrix (i.e. drying, frying, roasting) result in higher losses of provitamin A carotenoids. Degradation also occurs during the storage of dried products (e.g. from sweet potato, maize, cassava) at ambient temperature, and a short shelf life is a constraint that should be considered when foods are biofortified for provitamin A. Iron and zinc retention were high for common beans (Phaseolus vulgaris) and cowpeas (Vigna unguiculata), indicating that iron and zinc were mostly preserved during cooking (with/without soaking in water)

Cross-cultural development of hibiscus tea sensory lexicons for trained and untrained panelists

Given the growing interest in high quality hibiscus teas and the scarcity of information about their sensory profile, lexicons were developed in French, Portuguese, and English. Twenty-two samples, including freshly prepared and ready-to-drink (RTD) infusions, syrups, concentrates, and an instant tea were evaluated by trained panelists, resulting in 21 defined and referenced descriptors, subsequently assembled in a sensory wheel. The vocabulary used by untrained panelists was investigated in Senegal, Portugal, France, and United Kingdom through professional meetings (n = 30), consumer focus groups (n = 75) and check-all-that-apply (CATA) studies (n = 490), resulting in graphical lexicons with 27 sensory and 15 overall impression terms. Training, food culture, and product familiarity influenced results. Trained panelists used precise terms to describe the aromatic profile of hibiscus teas (e.g., “reminiscent of dried hibiscus flowers,” with “berry,” “raisin,” “hay,” and “sweet” aromatic notes), whereas untrained ones were more prolific in general expressions (e.g., “strong in hibiscus” in Senegal; “floral” and “fruity” in Europe). Practical applications This work provides a foundation for sensory research on hibiscus teas and practical support for product optimization processes, whether through hibiscus cultivar selection and breeding, improvement of harvest and postharvest operations or tea processing methods. Moreover, new lexicons will facilitate communication between the actors involved in the development, production, and marketing of hibiscus extracts and products thereof across Africa, Europe, and North/South America. Finally, potential drivers of hibiscus tea acceptance in both traditional and new markets are also identified

Use of sensory and physico-chemical parameters to understand consumer perception of attiéké, a fermented cassava product

Background: Cassava breeding research programs focused initially on agronomic performance but in recent years they have con-sidered the processability and the organoleptic properties of the final product, to increase the adoption of new varieties. One important cassava foodstuff is attiéké, a fermented and granular product, so it is necessary to determine criteria used by attiéké processors to select raw cassava and the characteristics leading consumers to like this product. This study assessed the attiéké pro-duction process, the criteria associated with the quality of attiéké, the sensory drivers of consumer acceptance, and their thresholds. Results: The total processing yield of attiéké varied according to the cassava variety and depended primarily on the fermentation-pressing yield. However, it was not correlated either with the peeling yield or with morphological characteristics of cassava roots. The production of a ton of attiéké required about 150 h. Dry matter, organic acids, soluble sugars, total pectin, and the pH of raw material and attiéké varied depending on the cassava variety. Ten discriminating sensory attributes of attiéké were identified. Consumer testing showed that overall liking for attiéké was associated with sourness, texture, and brightness. Acceptable sensory score thresholds were 1.67–2.18 for sour odor, 4.75 to 6.3 for cohesiveness, and 5.4 to 6.3 for ‘mouth feel sensation’. Attiéké dry matter correlated positively with cohesiveness and moldability. Conclusions: Several potential solutions are discussed to improve the adoption of cassava varieties for attiéké production. How-ever, further studies need to be carried out to translate the sensory thresholds of texture attributes into robust instrumental methods because texture is an important attribute of attiéké in addition to sourness

Characteristics of Different Systems for the Solar Drying of Crops

Solar dryers are used to enable the preservation of agricultural crops, food processing industries for dehydration of fruits and vegetables, fish and meat drying, dairy industries for production of milk powder, seasoning of wood and timber, textile industries for drying of textile materials. The fundamental concepts and contexts of their use to dry crops is discussed in the chapter. It is shown that solar drying is the outcome of complex interactions particular between the intensity and duration of solar energy, the prevailing ambient relative humidity and temperature, the characteristics of the particular crop and its pre-preparation and the design and operation of the solar dryer