Effect of preliminary and culinary processing on amino acid content and protein quality in frozen French beans

Abstract

The aim of the study was to evaluate the content of amino acids and protein quality of French bean pods. The investigated material consisted of the raw vegetable, fresh pods cooked to consumption consistency, and two kinds of frozen products stored for 12 months at )20°C and then prepared for consumption: frozen beans obtained using the traditional method (blanching before freezing) and frozen products of the ready-toeat type (cooking before freezing). A comparison of the amino acid content in the product prepared for consumption showed that the lowest quantities were found in French beans obtained using the traditional method; products obtained using the modified technology and beans cooked directly after harvest had similar levels of most amino acids. The content of amino acids in 16 g N was less varied than in 100 g of the product. The protein in all the three products prepared for consumption as well as that in fresh bean pods hardly differs, as confirmed by the values in the essential amino acid index (EAA). The first limiting amino acid was methionine with cystine and the second was lysine.

Content of amino acids and the quality of protein in as‐eaten green asparagus (Asparagus officinalis L.) products

“…This proportion is comparable with other vegetable species : 44% in kale (Lisiewska et al. , 2008); 41% in French bean (Kmiecik et al. , 2008); and 36% in Brussels sprouts (Lisiewska et al.…”

“…Different amino acids are lost in different plants probably because of differences in their structural composition and susceptibility to destruction by heat (Ziena et al. , 1991; Kmiecik et al. , 2008; Lisiewska et al.…”

Chemical, Physicochemical, Nutritional, Microbiological, Sensory and Rehydration Characteristics of Instant Whole Beans (Phaseolus vulgaris)

“…In the instant whole beans obtained in this study, 75 % of the essential amino acids (lysine, threonine, isoleucine, valine, leucine, phenylalanine and tyrosine) had EAA=essential amino acids, NEAA=non-essential amino acids, CS=chemical score, EAAI=essential amino acid index, PER=protein effi ciency ratio a value greater or equal to the reference standard for adults (20), while the tryptophan and sulphur-containing amino acids (methionine and cysteine) were the limiting amino acids, as it has been observed in other bean varieties and legume seed protein isolates (37,38). In contrast, the protein quality of instant whole beans in terms of chemical score was 95 %, in comparison with the values of 80-82 % reported for other varieties of cooked beans (37,39), while the essential amino acid index was 104.1 %, indicating a high nutritive value of the protein but lower than the reported values of 112-115 % for raw and processed French beans (40 …”

The effect of processing on the amino acid content in green cauliflower

“…The present authors agree that changes in the level of amino acids are not only determined by the pre-treatment parameters but also by the species in question and the edible parts of the vegetable, i.e. the particular tissue under investigation (Klein and Mondy 1981, Murcia et al 2001, Kmiecik et al 2008b, Kmiecik et al 2009. The literature shows that the retention of amino acids varies depending on the factors mentioned above: statistically significant losses may be found (Candela et al 1997, Diasolua-Ngudi et al 2003; but also, as in the present investigation, no significant changes might be observed (Khalil and Mansour 1995, Murcia et al 2001, El-Adawy 2002, Korus et al 2003; or, as reported by Mutia and Uchida (1993), the content of amino acids in edible parts may increase significantly.…”

“…The highest EAA index characterizing protein quality was registered by raw cauliflower (117), followed by the product from traditionally frozen cauliflower (114), with the lowest found in the remaining samples (106). The limiting amino acid in the protein of various vegetable species is usually methionine with cystine (Choi and Lee 1999, Diasolua-Ngudi et al 2003, Korus et al 2003, Kmiecik et al 2008b, though it may also be lysine (Ishida et al 2000, Ayaz et al 2006, histidine (Lopez et al 1996) or tyrosine with phenylalanine (Kmiecik et al 2009). …”