RESUMEN
Celiac disease ranks highest among immunological disorders attributed to gluten consumption thus, posing great demands on gluten-free products. Rice is a gluten-free cereal with promising dietary applications. Ofada rice, a native southwestern Nigerian variety, can be improved with sourdough technology to develop functional aglutenic bread. Ofada rice sourdough bread (ORSB) was made with Fructilactobacillus fructivorans RY1, Weissella viridescens RY9 and Lactobacillus acidophilus RY10 as individual and combined starter cultures. Physical qualities, proximate contents, sensorial attributes and shelf-life of the ORSBs were evaluated. Sourdough bread with the highest (3.10 cm3/g) and lowest specific volumes (2.02 cm3/g) were the sample made single culture of W. viridescens and F. fructivorans, respectively. The highest crude protein (8.48 %) was found in ORSB with only F. fructivorans and ORSB with L. acidophilus singly had the highest content (0.44 %) of crude fibre. Nevertheless, the least crude protein (5.25 %) and crude fibre (0.28 %) were observed in samples containing F. fructivorans, W. viridescens, and L. acidophilus as combined starters. The sourdough bread with F. fructivorans as a starter scored best for texture and overall acceptability. The ORSBs had shelf-life ranging from three to four days. It was revealed in the study that using the specific LAB starters could improve the physicochemical attributes and acceptability of bread from Ofada rice flour.
RESUMEN
BACKGROUND: In addition to improving soil fertility and crop production, earthworms have been found to be useful in the removal of contaminants from soil, known as vermiremediation. Previous studies on vermiremediation have focused primarily on organic wastes, with relatively less attention paid to inorganic contaminants. In addition, some basic terms used in environmental health studies have often not been properly clarified. OBJECTIVES: The present study is a review of the state of the literature on the effectiveness of using earthworms to remediate organic and inorganic (metal) soil contaminants. Earthworms' actions in remediation of organic and inorganic contaminants are described. Some terms that are used interchangeably in environmental health are clarified. The challenges and limitations of vermiremediation are highlighted. METHODS: A systematic literature search was conducted to access online academic publications indexed in Google Scholar, PubMed, Scopus, Clarivate Analytics (Web of Science), ScienceDirect, ResearchGate and Springer Link. A total of 165 publications on the subject matter were accessed, out of which 47 were used for the review. DISCUSSION: Empirical and theoretical information from the literature showed evidence of the significant contributions of earthworms to the removal of soil organic contaminants and metals. Earthworms indirectly facilitate the conversion of organic contaminants by promoting microbial and enzyme activities. Some organic contaminants are directly taken up through dermal and intestinal absorption and accumulated by preferential sequestration in sub-organismic and tissue fractions of earthworms. Metals are directly removed and accumulated by the mechanism of detoxification and sequestration, via metallothioneins induction. The terms 'contaminants' and 'pollutants' have different meanings and should not be used interchangeably. Although vermiremediation presents an ideal clean-up technique, it is limited in application to only mildly contaminated soil environments. Ethical concerns should not pose a serious issue because vermiremediation simply takes advantage of earthworms' natural soil-conditioning abilities. Many vermiremediation processes, especially of organic wastes, are harmless to earthworms, improving the soil for their growth and survival. CONCLUSIONS: Vermiremediation presents a good long-term biological option to clean up mildly contaminated soil. It may be deployed as a secondary measure to rid the soil of residual contaminants after applying physicochemical remediation techniques to an overtly polluted soil environment. COMPETING INTERESTS: The authors declare no competing financial interests.
