慶英会 塾長｜慶應義塾大学卒・英検1級
中高一貫校の学校英語・NEW TREASURE・英検対策を専門とするオンライン個別指導塾です。塾長紹介
NEW TREASURE Stage5 Third EditionのLesson7は「弱臭納豆の開発」を題材に、伝統食品と商品革新を考える読解です。大学入試や定期テストでは、発酵の知識だけでなく、顧客の好み、試作品の評価、実験の証拠、広告の表現がどう結びつくかを理解することが重要です。慶英会が独自制作した英文8段落と32問・全解答・和訳・英作文で初見読解を学べます。
【使用版・独立性】Ｚ会のStage5 Third EditionのLesson7題材を確認した上で制作した補助教材です。以下のHorizon Foodsという企業、商品試験と40人の回答はすべて創作であり、特定のメーカーの商品・売上や研究データを示しません。発酵・低臭納豆の研究史に関する記述にはJ-STAGEで公開されている研究論文を参照します。出版社の本文・解答の無断転載はしていません。
目次：低臭納豆の研究／独自長文／32問／全解答／復習・要約／FAQ
低臭納豆とは？伝統と科学技術をどう両立するか
納豆は一般に納豆菌（Bacillus subtilis〈natto〉）による発酵を利用した大豆食品です。発酵に関連する成分が風味・食感・香りに関係します。日本醸造協会誌に掲載された2004年の「低臭納豆の開発」は、従来の特徴的な香りを低減する商品開発が研究対象になっていたことを示しています。ただし「弱い匂い」は無臭を意味せず、製品や保存条件による違いを一つの結論にまとめるのは不正確です。
- Fermentation：微生物などの作用を用いる発酵。
- Product attribute：香り・味・食感・価格など顧客が比較する特徴。
- Consumer preference：顧客の好み。万人で一致するとは限らない。
- Blind comparison：ブランド名などの先入観を抑える評価。
- Trade-off：一方を改善すると別の費用・品質との調整が必要になること。
- Evidence-based claim：測定した内容の範囲を超えない広告・説明。
読解で重要な対比は、milder smell（香りが弱い）とbetter product（製品全体として優れている）の違いです。香りが弱いと答えた人数だけで「売れる」「健康的」とは証明できません。製品属性と購入判断、さらに健康への影響は別のデータが必要です。
慶英会独自長文｜Innovation in a Traditional Food
以下は架空企業の商品開発を扱うオリジナル英文です。学校のRead本文を転載したものではありません。各段落について「どの製品属性」「どのデータ」「何がまだ不明か」を確認して読んでください。
Paragraph 1 — A familiar food and an unfamiliar customer. Natto is familiar to many people in Japan, but it is not necessarily easy to introduce to someone who has never tried it. Its sticky texture, distinctive aroma and characteristic taste can produce strong reactions. A company trying to develop a less strongly smelling product therefore faces two different questions. Can it change the characteristics that some customers dislike, and can it do so without losing what others value about traditional natto? These questions show why innovation is not simply the replacement of old products with new ones. It often involves deciding which qualities should be preserved and which should be adjusted for a particular audience.
Paragraph 2 — Fermentation and research. Natto is made through fermentation involving Bacillus subtilis, commonly called the natto bacterium. Scientific research has investigated how microbial activity contributes to flavor, texture and odor. A paper about the development of weak-smelling natto, published in a Japanese brewing journal in 2004, illustrates that odor reduction has been treated as a research and product-development problem. However, the phrase weak-smelling does not mean completely odorless, and one study should not be treated as proof that every such product tastes identical to conventional natto. Food characteristics depend on the particular product, production conditions and storage. Responsible explanations distinguish research findings from advertising promises.
Paragraph 3 — A fictional product team. In a fictional classroom business case, a small company called Horizon Foods plans to sell two natto products. The first is its existing recipe; the second is a prototype designed to have a milder aroma. Before choosing a package design, the team asks potential customers what matters most to them. Some say they dislike a strong smell, while others say that texture and taste are more important. The manager initially wants to advertise the prototype as “better natto for everyone.” A researcher objects. No survey has demonstrated that everyone would prefer it, and the word better conceals the fact that different customers may value different attributes. The team decides to test specific claims instead.
Paragraph 4 — Separating product attributes. The team identifies four qualities to study: perceived smell strength, taste, texture and overall preference. Participants will rate each attribute independently rather than answer only whether they like the product. This distinction matters because a person might report that the prototype smells milder but still prefer the taste of the existing recipe. A product can improve one attribute without improving the overall experience. The team also recognizes that a blind comparison may reduce the influence of packaging and brand expectations. It plans to use neutral labels so that participants do not know which sample is described as the innovation. Even then, a small test cannot perfectly predict sales.
Paragraph 5 — An invented dataset. To illustrate how a report should be read, imagine a group of forty volunteers in a classroom exercise. All forty sample both fictional products in a balanced order. Twenty-six describe the prototype’s aroma as milder, but twenty-two choose the conventional version when asked which they would purchase. These measures are not contradictory. The first concerns the perceived intensity of one attribute, while the second concerns a broader buying preference. Moreover, the exercise has no statistical design sufficient to represent all shoppers in Japan or overseas. Repeating the comparison with different audiences and with clearly specified methods might provide stronger evidence. The numbers are fictional and should never be quoted as market research.
Paragraph 6 — Tradition as a source of ideas. At a meeting, one employee argues that protecting tradition requires keeping every feature of the original product. Another suggests that tradition is maintained not only by preserving a recipe but also by allowing new generations to encounter it. The disagreement turns into a practical discussion about market segments. Long-time customers may prefer a recognizable flavor, while newcomers may welcome a milder option. Offering both products could preserve choice, but it would also create extra production and inventory costs. The team must therefore consider the possible gain in customers against the complexity of maintaining two versions. Cultural respect and commercial practicality can support each other, but neither automatically guarantees success.
Paragraph 7 — Honest communication. The marketing department drafts the sentence, “Our new natto has no smell and is healthier than ordinary natto.” The team removes it. The prototype was designed to smell milder, not to be entirely odorless, and the fictional tasting exercise did not measure health effects. The revised description reads, “A natto prototype developed for people who prefer a milder aroma.” This phrase is narrower and more accurate. It states a design purpose without claiming that the product is universally superior. The team also agrees that any future health-related claim would require suitable evidence and compliance with the relevant rules for food labeling. A convincing advertisement should not exceed what the research supports.
Paragraph 8 — The broader lesson. The case ends with a decision to continue testing rather than promise an immediate launch. The researchers know that fermentation, consumer expectations and business costs interact. They have also learned that innovation is not just a scientific achievement or an attractive marketing phrase. It is a process of turning customer needs into testable product attributes, weighing trade-offs and communicating results fairly. A responsible company can respect an established food culture while trying new approaches, but it must identify exactly what has changed and who might benefit. For students reading about innovation, the central question is not whether tradition or change always wins. It is how evidence can guide their combination.
独自32問｜本文・データ・語彙・英作文
第1部 製品開発と数値16問
問1. What two questions does the company face in paragraph 1?
問2. What microorganism is associated with natto fermentation?
問3. Does weak-smelling mean completely odorless?
問4. What does Horizon Foods plan to compare?
問5. Why did the researcher object to ‘better natto for everyone’?
問6. What are the four product attributes to be rated?
問7. Why would the team use neutral labels?
問8. How many fictional volunteers joined the classroom comparison?
問9. How many described the prototype as milder?
問10. How many would purchase the conventional version?
問11. What percentage of volunteers said the prototype smelled milder?
問12. What percentage preferred buying the conventional version?
問13. Why are the two results not contradictory?
問14. What two business costs might arise from offering both versions?
問15. Why was ‘healthier than ordinary natto’ removed from the advertisement?
問16. What is the author’s main conclusion?
第2部 語彙・論理8問
問17. What does distinctive in paragraph 1 mean?
問18. The word prototype means (A) experimental version (B) official regulation (C) traditional recipe.
問19. The word attributes in paragraph 4 means what?
問20. What does independently mean in paragraph 4?
問21. The phrase even then in paragraph 4 signals what?
問22. What does segments mean in paragraph 6?
問23. The phrase not only … but also … in paragraph 6 expresses what?
問24. The word universally in paragraph 7 most nearly means what?
第3部 英文和訳・英作文・要約8問
問25. Translate: A product can improve one attribute without improving the overall experience.
問26. Translate: Offering both products could preserve choice, but it would also create extra production and inventory costs.
問27. Translate: An attractive marketing phrase should not exceed what the research supports.
問28. Write: 「香りの弱さと購買の好みは異なる指標だ」。
問29. Write: 「すべての顧客が新製品を好むとは限らない」。
問30. Write: 「その試験は健康上の優位性を確かめていない」。
問31. Explain one advantage and one possible drawback of offering two versions.
問32. Provide a two-sentence summary.
全32問の解答・詳しい理由
解答1〜16｜本文の事実・数値
解答1：How to reduce disliked features while preserving valued features.
解説：新規顧客と既存顧客の価値の違いが問題。
解答2：Bacillus subtilis (natto).
解説：納豆菌に関する基本的な記述。
解答3：No.
解説：弱臭は臭いが皆無という意味ではない。
解答4：A conventional recipe and a milder-aroma prototype.
解説：Horizon Foodsは演習用の架空企業。
解答5：No evidence supported a universal preference.
解説：好みの多様性を過度に一般化しない。
解答6：Smell strength, taste, texture and overall preference.
解説：単一指標と総合評価を分ける。
解答7：To reduce packaging or brand expectation effects.
解説：先入観による評価差を小さくする目的。
解答8：Forty.
解説：実在の市場調査値ではない。
解答9：Twenty-six.
解説：臭いの強さという一つの項目。
解答10：Twenty-two.
解説：購入選好という別の項目。
解答11：65% (26/40).
解説：40人中26人。
解答12：55% (22/40).
解説：40人中22人。
解答13：They measure different things: aroma strength and buying preference.
解説：同じ質問への回答ではない。
解答14：Additional production and inventory costs.
解説：少量多品種化の複雑さに関する本文の議論。
解答15：Health effects were not measured.
解説：感想の調査から健康への因果効果を主張できない。
解答16：Innovation should balance customer needs, evidence, tradition and trade-offs.
解説：技術・文化・採算と検証の統合。
解答17〜24｜語彙・論証
解答17：Characteristic or clearly recognizable.
解説：他と区別できる特徴的な性質。
解答18：(A) experimental version.
解説：試作段階の製品。
解答19：Features or qualities of a product.
解説：製品の特徴・属性。
解答20：Each attribute is evaluated separately.
解説：複数評価軸を分けるという意味。
解答21：A limitation that remains despite efforts to reduce bias.
解説：改善しても残る制約を示す。
解答22：Groups of customers with different preferences.
解説：顧客の嗜好別グループ。
解答23：The idea that tradition can involve preservation and adaptation.
解説：片方を排除せず両面を述べる。
解答24：For everyone or in every case.
解説：特定の人への適合と普遍性を区別。
解答25〜32｜英訳・英作文
解答25：製品は、体験全体を改善しないまま、ある一つの特徴だけを改善することがある。
解説：without＋動名詞で「〜することなく」。
解答26：両製品を提供すれば選択肢を維持できるかもしれないが、追加の製造費と在庫費も発生するだろう。
解説：could/wouldの仮定的な予測。
解答27：魅力的な宣伝文句であっても、研究が裏付ける範囲を超えてはならない。
解説：whatは研究が支持する内容を指す名詞節。
解答28：A milder aroma and purchasing preference are different measures.
解説：measureは測定項目。
解答29：Not all customers necessarily prefer the new product.
解説：部分否定Not allとnecessarily。
解答30：The test did not assess any health advantage.
解説：評価対象外のことを示す。
解答31：It offers more choice but increases production or inventory complexity.
解説：顧客価値と固定・変動費のトレードオフ。
解答32：Weak-smelling natto development illustrates how innovation can respond to consumer preferences without abandoning tradition. However, companies must measure distinct product attributes and avoid advertising claims that go beyond available evidence.
解説：目的→証拠→留保の三要素。
英文要約例と7日間の復習
英文要約モデル：Developing natto with a milder smell illustrates how businesses can innovate while respecting tradition. A fictional company compares a conventional recipe with a new prototype and finds that customers value several attributes differently. Even when many participants notice a milder aroma, they may still prefer the older product for purchase. The study does not justify universal or health-related claims. Responsible innovation requires careful testing, attention to different customers and honest marketing.
要約ではEven when / not necessarily / mayなど、結論の強さを調整する英語を残します。商品開発の成功を根拠のない一文で断定せず、用途と顧客層を区別することが大切です。
- Day1：本文8段落に見出しを付ける。
- Day2：実験の二つの指標（臭いの強さ・購買意向）を表に分ける。
- Day3：問1〜16の根拠を英文中から引用せず位置で説明する。
- Day4：問17〜24の接続語と限定表現を言い換える。
- Day5：問25〜30の和訳・英作文を独力で再現する。
- Day6：学校のLesson7指定本文とWorkbookの表現を確認する。
- Day7：60〜80語の英語要約を自分で作り、数値の意味の取り違えを修正する。
よくある質問
Q. 低臭納豆はまったく匂わないのですか？
A. 「匂いが弱い」ことと「完全に匂わない」ことは別です。低臭という表現だけから完全無臭を保証するものではありません。
Q. 納豆の香りが弱ければ売上が増えますか？
A. 断定できません。香り以外にも味・価格・食感・購入する人の好みが関わります。本文の40人調査は架空の例題です。
Q. このページの英文はＺ会のLesson7本文ですか？
A. いいえ。テーマに関連する慶英会独自の教材であり、出版社の英文・問題・解答を転載したものではありません。
関連教材・慶英会の学習相談
科学・ビジネス題材の長文では、専門用語を知っていても広告の主張と実験結果の範囲を取り違えることがあります。慶英会では学校のLesson進度、定期テスト答案の失点、英作文を組み合わせた個別指導を行います。最大1か月無料体験・学習相談はこちら。
参考にした主な公式情報・研究
Ｚ会2026年NEW TREASURE公式カタログ（Stage5 Lesson7）／Takemura（2004）Development of Weak-Smelling Natto／Development of New Itohiki-Natto and Odor of Natto Type Foods。研究の一般説明を参照し、企業や数値の例は創作です。
次のテーマ：Stage5 Lesson8｜鳥・魚の集団行動32問で、生物の行動を説明する数理モデルと観測された事実を区別する練習に進みましょう。
Lesson7の学習を総合問題に接続する：授業範囲の読解を復習したら、Stage5全10Lessonの独自総合テスト60問（全解答）で初見の英問英答・和訳・英作文を確認できます。専門的なテーマ語彙に不安がある場合は、Stage5の重要語彙・熟語100選（独自例文100文・確認40問）を先に復習してください。いずれも慶英会が独自に作成した無料教材です。
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慶英会 塾長｜慶應義塾大学卒・英検1級。中高一貫校の学校英語・NEW TREASURE・英検対策を専門としています。塾長の経歴・指導方針を確認する